Spirulina (Blue Green Algae) A Protein Treasure (70% of Protein)

Spirulina (Blue Green Algae) A Protein Treasure (70% of Protein)

 

Spirulina

Spirulina are multicellular and filamentous blue-green microalgae. Arthrospira platensis is the most common and widely available spirulina grows in water, can be harvested and processed easily and has significantly high macro- and micronutrient contents. It is used as human food as an important source of protein and is collected from natural water, dried and eaten.

        Spirulina is a primitive organism originating some 3.5 billion years ago that has established the ability to utilize carbon dioxide dissolved in seawater as a nutrient source for their reproduction. It is a photosynthesizing cyanophyte (blue-green algae) that grows vigorously in strong sunshine under high temperatures and highly alkaline conditions.

       In 1967 spirulina was established as a “wonderful future food source” in the International Association of Applied Microbiology (Sasson, 1997). Analysis of the nutritional properties of spirulina showed first and foremost an exceptionally high protein content, of the order of 60–70 percent of its dry weight; it also showed the excellent quality of its proteins (balanced essential amino acid content).

The spirulina Contains:

Protein: Spirulina contains unusually high amounts of protein, between 55 and 70 percent by dry weight, depending upon the source (Phang et al., 2000). It is a complete protein, containing all essential amino acids, though with reduced amounts of methionine, cystine, and lysine, as compared to standard proteins such as that from meat, eggs, or milk; it is, however, superior to all standard plant protein, such as that from legumes.

Essential fatty acids: Spirulina has a high amount of polyunsaturated fatty acids (PUFAs), 1.5–2.0 percent of 5–6 percent total lipid. In particular spirulina is rich in γ-linolenic acid (36 percent of total PUFAs), and also provides γ-linolenic acid (ALA), linoleic acid (LA, 36 percent of total ), stearidonic acid (SDA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and arachidonic acid (AA). Spirulina has high quality protein content (59–65 percent), which is more than other commonly used Plant sources such as dry soybeans (35 percent), peanuts (25 percent) or grains (8–10 percent). A special value of spirulina is that it is readily digested due to the absence of cellulose in its cell walls.

Vitamins: Spirulina contains vitamin B1 (thiamine), B2 (riboflavin), B3 (nicotinamide), B6 (pyridoxine), B9 (folic acid), B12 (cyanocobalamin), vitamin C, vitamin D and vitamin E.

β-carotene: Spirulina contains large amounts of natural β-carotene and this β-carotene is converted into vitamin A. According to the findings of the National Cancer Institute, United States of America, an intake of 6.0 mg β-carotene daily may be effective in minimizing the risk of cancer.

Minerals: Spirulina is a rich source of potassium, and also contains calcium, chromium, copper, iron, magnesium, manganese, phosphorus, selenium, sodium and zinc.

Amino acids: Spirulina protein has a balanced composition of amino acids, with concentrations of methionine, tryptophan and other amino acids (Lysine, Phenylalanine, Tyrosine, Leucine, Glutamic acid, Aspartic acid, Cystine, Serine, Arginine, Histidine, Threonine, Proline, Valine, Isoleucine, Alanine and Glycine ) almost similar to those of casein.

Applications of Spirulina

Immune system enhancement: The Academy of Chinese Military Medical Sciences showed that spirulina could effectively improve the survival rate of mice after exposure to a lethal dose of radiation, prolong their survival time, and improve their immunity and activity of superoxide dismutase (SOD). Proved to be effective in lowering blood lipid, combating fatigue and increasing the level of immunoglobulin A (IgA) and immunoglobulin M (IgM). Phycocyanin of Spirulina platensis inhibits the growth of human leukemia K562 cells when supplemented with diet (Liu et al., 2000).

Nutritional supplement: Spirulina is rich in high quality protein, vitamins, minerals and many biologically active substances (Becker, 1994). Its cell wall consists of polysaccharide which has a digestibility of 86 percent, and could be easily absorbed by the human body. Spirulina is well known to have a very high iron content, it was tested against a typical iron supplement, iron sulfate. Spirulina-fed rats absorbed 60 percent more iron that rats fed the iron supplement. This study suggested that there is a highly assimilable form of iron in spirulina. A study also showed that it was effective in correcting anaemia in rats. A study showed the blood hemoglobin content increased from 10.9 to 13.2 (±21 percent) for human (female), a satisfactory level no longer considered anaemic (Henrikson, 1989). Spirulina significantly reduced the blood glucose level of both male and female.

Food source: when the algal cells or filaments of spirulina are transformed into powder it can provide the basis for a variety of food products, such as soups, sauces, pasta, snack foods, instant drinks and other recipes. Spirulina can be used as a partial supplementation or complete replacement for protein in aquafeeds.

Use as fertilizer:  blue-green algae replacing chemical fertilizers and rebuilding the structure of depleted soils (FAO, 1981)

Protein supplement in poultry and livestock feeds:

Fishmeal, groundnut meal and soybean meal can be partially replaced by spirulina in the preparation of diets of fish, poultry, cattle and domestic animals (Venkataraman, Somasekaran and Becker, 1994; El- Sayed, 1994; Britz, 1996).

Colorant in food products:

The blue-green colour of spirulina is due to two pigments: phycocyanin (blue) and chlorophyll (green). These two pigments are combined with another group of pigments known as carotenoids (red, orange and yellow). This phycocyanin extracted from spirulina was first marketed in 1980 by the Dainippon Ink & Chemicals Inc. under the brand name “Lina Blue-A”. This was mainly used as a food colourant, as an edible dye in ice creams and as a natural dye in the cosmetics industry. However, as the pigment was light sensitive, special care must be taken in protecting it from bleaching (Vonshak, 1990).

 REFERENCES

    Banerjee, M. & Deb, M. 1996. Potential of fly ash and Spirulina combination as a slow release fertilizer for rice field. Cientifica Jaboticabal, 24: 55–62.

    Becker, E.W. 1988. Microalgae for human and animal consumption. In M.A. Borowitzka & L.

    Borowitzka, eds. Micro-algal Biotechnology, pp. 222–256. Cambridge, Cambridge University Press.

    Becker, E.W. 1994. Microalgae. In Nutrition. pp. 196–249. Cambridge, Cambridge University Press.

    Belay, A., Yoshimichi, O., Miyakawa, K. & Shimamatsu, H. 1993. Current knowledge on potential health benefits of Spirulina. J. Appl. Phycol., 5: 235–241.

    M. Ahsan, B. Habib, Mashuda Parvin, FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS, Rome, 2008. A review on culture, production and use of spirulina as food for human and feed for domestic animal and fish.

Industrial Production of Beer

Industrial Production of Beer

Beer Production

Beer is a beverage containing alcohol, extract, and carbon dioxide. Beer is prepared from barley malt, raw hops or other hop products, brewing water, and top- or bottom-fermenting yeast. The alcohol must be produced exclusively from these ingredients, which are converted to fermentable products during the brewing process. The word beer comes from the Latin word ‘‘bibere’’ (to drink), which is the origin of the Old English word ‘‘be~or’’ (the brewed). The industrial production of beer process consist of various steps.

Milling

Beginning In the brew house, different types of malt (barley, corn, rice) are crushed together to break up the grain kernels in order to extract fermentable sugars to produce a milled product called grist.

Mash Conversion

The grist is then transferred into a mash tun and mixed with heated water in a process called mash conversion. The conversion process uses natural enzymes in the malt to break the malt’s starch down into sugars. Mashing allows the enzymes in the malt (primarily, α-amylase and β-amylase) to break down the starch in the grain into sugars, typically maltose to create a malty liquid called wort. The overall process will take up to 60-120 minutes.

Optimal rest temperatures for major mashing enzymes

 

Temp °C	Temp °F	Enzyme	Breaks down
40–45 °C	104.0–113.0 °F	β-Glucanase	β-Glucan
50–54 °C	122.0–129.2 °F	Protease	Protein
62–67 °C	143.6–152.6 °F	β-Amylase	Starch
71–72 °C	159.8–161.6 °F	α-Amylase	Starch

Lautering

The mash is then pumped into the lauter tun, where a sweet liquid (known as wort) is separated from the grain husks.

Boiling

The wort is then collected in a vessel called a kettle, where it is brought to a controlled boil before the hops are added. Hope are important as it gives characteristic flavour to the beer. Hops are a female flower of Humulus lupulus . Bitter and aroma imparting hops are used for brewing. They both differ in essential oil and alpha acid contents. Bitter hops are rich in alpha acid while aroma hops are rich in essential oils

Wort separation and cooling

After boiling, the wort is transferred into a whirlpool for the wort separation stage. During this stage, any malt or hop particles are removed to leave a liquid that is ready to be cooled, the WORT in a Plate Heat Exchanger from 100 °C to about 10 °C in an hour.

Fermentation

To start the fermentation, yeast is added during the filling of the vessel. Saccharomyces cerevisiae is used for beer manufacturing. Yeast converts the sugary wort into beer by producing alcohol, a wide range of flavors, and carbon dioxide. The cooled wort is transferred into a fermentation vessel to which the yeast has already added. If the beer being made is an ale, the wort will be maintained at a constant temperature of 20° C) for about two weeks. If the beer is a lager, the temperature will be maintained at (9-12°C) for about six weeks. Since fermentation produces a substantial amount of heat, the tanks must be cooled constantly to maintain the proper temperature. When fermentation has finished, the beer is cooled to about (0° C). This helps the remaining yeast settle to the bottom of the fermenter, along with other undesirable proteins that come out of solution at this lower temperature.

When the yeast first hits the wort, concentrations of glucose (C6H12O6) are very high, so through diffusion, glucose enters the yeast (in fact, it keeps entering the yeast as long as there is glucose in the solution). As each glucose molecule enters the yeast, it is broken down in a 10-step process called glycolysis. The product of glycolysis is two three-carbon sugars, called pyruvates, and some ATP (adenosine triphosphate), which supplies energy to the yeast and allows it to multiply. The two pyruvates are then converted by the yeast into carbon dioxide (CO2) and ethanol (CH3CH2OH, which is the alcohol in beer)

Maturation

After fermentation, the young “green” beer needs to be matured in order to allow both a full development of flavors and a smooth finish.

Filtration & carbonation

Now that most of the solids have settled to the bottom, the beer is slowly pumped from the fermenter and filtered to remove any remaining solids. From the filter, the beer goes into another tank, called a bright beer tank. This is its last stop before bottling or kegging. Here, the level of carbon dioxide is adjusted by bubbling a little extra CO2 into the beer through a porous stone. once completed, the beer is ready to be packaged

After filling the beer passed through pasteurizer before dispatch. 

Reference

Text Book of Microbiology : RC Dubey

Evan Evans (2011). The Oxford Companion to Beer. Oxford University Press. p. 236. ISBN 9780195367133. Archived from the original on 23 December 2019.

 Chris Boulton (20 May 2013). Encyclopaedia of Brewing. John Wiley & Sons. p. 111. ISBN 9781118598122. Archived from the original on 21 May 2016.

ChAd vaccine against Covid-19

ChAd vaccine against Covid-19

ChAd vaccine protects upper and lower respiratory tracts against SARS-CoV-2 (Covid-19)

Chimpanzee adenovirus vectors

Article Showed the researcher used ChAd vector as vaccine platforms for SARS-CoV-2. ChAd-SARS-CoV-2-S encodes for SARS CoV-2 S protein with the two indicated proline mutations. Single dose immunization of a stabilized S protein-based vaccine via an intramuscular route induced S- and RBD-specific binding as well as neutralizing antibodies. Vaccination with one or two doses protected mice expressing human ACE2 against SARS-CoV-2 challenge, as evidenced by an absence of infectious virus in the lungs and substantially reduced viral RNA levels in lungs and other organs.

Immunization with ChAd-SARS-CoV-2-S induces both neutralizing antibody and antigen-specific CD8+ T cell responses. While a single intramuscular immunization of ChAd-SARS-CoV-2-S confers protection against SARS-CoV-2 infection and inflammation in the lungs, intranasal delivery of the vaccine induces mucosal immunity, provides superior protection, and possibly promotes sterilizing immunity, at least in mice that transiently or stably express the hACE2 receptor. Image credit: Hassan et al, doi: 10.1016/j.cell.2020.08.026.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a positive-sense single-stranded RNA virus that was first isolated in late 2019 from patients with severe respiratory illness in Wuhan, China. SARS-CoV-2 is related to two other highly pathogenic respiratory viruses, SARS-CoV and Middle East respiratory syndrome coronavirus (MERS-CoV). SARS-CoV-2 infection results in a clinical syndrome, Coronavirus Disease 2019 (COVID-19) that can progress to respiratory failure and also present with cardiac pathology, gastrointestinal disease, coagulopathy, and a hyperinflammatory syndrome.

    Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)    

        The SARS-CoV-2 RNA genome is approximately 30,000 nucleotides in length. The 5’ two-thirds encode nonstructural proteins that enable genome replication and viral RNA synthesis. The remaining one-third encode structural proteins such as spike (S), envelope, membrane, and nucleoprotein (NP) that form the spherical virion, and accessory proteins that regulate cellular responses. The S protein forms homotrimeric spikes on the virion and engages the cell-surface receptor angiotensin-converting enzyme 2 (ACE2) to promote coronavirus entry into human cells.

        The SARS-CoV and SARS-CoV-2 S proteins are cleaved sequentially during the entry process to yield S1 and S2 fragments, followed by further processing of S2 to yield a smaller S2' protein. The S1 protein includes the receptor binding domain (RBD) and the S2 protein promotes membrane fusion.This form of the S protein is recognized by potently neutralizing monoclonal antibodies and could serve as a promising vaccine target. Single intranasal dose of ChAd-SARS-CoV-2-S induced high levels of neutralizing antibody and anti-SARS-CoV-2 IgA, and conferred virtually complete protection against infection in both the upper and lower respiratory tracts in mice expressing hACE2 receptor after adenoviral vector delivery or as a trans gene. It has the potential to control infection at the site of inoculation, which should prevent both virus-induced disease and transmission.

Immunogenicity of ChAd-SARS-CoV-2-S, groups of 4-week-old BALB/c mice were immunized by intramuscular inoculation with 10¹⁰ virus particles of ChAd-SARS-CoV 2-S or ChAd-control. Some mice received a booster dose four weeks later. Serum samples were collected 21 days after primary or booster immunization, and IgG responses against purified S and RBD proteins were evaluated by ELISA. Whereas ChAd-SARS-CoV-2-S induced high levels of S- and RBD-specific IgG, low levels were detected in the ChAd control-immunized mice.

Vaccine-induced memory CD8+ T cell and antigen specific B cell responses.

Intramuscular immunization with ChAd-SARS-CoV-2-S vaccine protects against               SARS- CoV-2 infection in the lung.

A single intranasal immunization with ChAd-SARS-CoV-2-S prevents SARS-CoV-2 infection in the upper and lower respiratory tracts of hACE2 transgenic mice. Recently established a more stringent, lethal SARS-CoV-2 challenge model in transgenic C57BL/6 mice that have eight inserted copies of the hACE2 gene driven by the K18 cytokeratin epithelial cell promoter. Within one week of SARS-CoV-2 inoculation by an intranasal route, K18- hACE2 mice develop severe lung infection and inflammation, immune cell infiltration, and compromised respiratory function that results in death. As an independent test of the efficacy of intranasal administration of ChAd-SARS-CoV-2-S, Researcher assessed its immunogenicity and protective efficacy in K18-hACE2 mice. Four-week old K18-hACE2 mice were inoculated via an intranasal route with 10¹⁰ viral particles of ChAd-control or ChAd-SARS-CoV-2-S. Serum samples were collected at four weeks post-immunization and humoral immune responses were evaluated. Intranasal immunization of ChAd-SARS-CoV-2-S but not ChAd-control induced high levels of S- and RBD specific IgG and IgA and neutralizing antibodies (GMT of 1/1,424) in serum. At day 30 post-vaccination, K18-hACE2 mice were challenged via an intranasal route with 10³ FFU of SARS-CoV-2. At 4 dpi, lungs, spleen, heart, nasal turbinates, and nasal washes were harvested and assessed for viral burden. Similar to that seen in BALB/c mice transiently expressing hACE2, intranasal immunization of ChAd-SARS-CoV-2-S conferred remarkable protection as judged by an absence of infectious virus in the lungs, no measurable viral  subgenomic/genomic RNA in the lungs or hearts, and very low levels of viral RNA in the nasal  turbinates or washes. Consistent with these results, after SARS-CoV-2 challenge, observed no induction of cytokine and chemokine mRNA (e.g., CCL2, CXCL1, CXCL10, 297 CXCL11, IL6, IFNβ, and IFNλ) in the lung homogenates of ChAd-SARS-CoV-2-S-immunized  compared to naïve mice, whereas ChAd-control vaccinated mice sustained high levels . Collectively, these data suggest that a single intranasal immunization of ChAd-SARS-CoV-2-S induces robust systemic and mucosal immunity that blocks SARS-CoV-2 infection in the upper and lower respiratory tract of highly susceptible K18-hACE2 transgenic mice, source from article.

Reference

A.O. Hassan et al. 2020. A single-dose intranasal ChAd vaccine protects upper and lower respiratory tracts against SARS-CoV-2. Cell, in press; doi: 10.1016/j.cell.2020.08.026

Genetically engineered (GE) Aedes aegypti Mosquito

Genetically engineered (GE) Aedes aegypti Mosquito

Aedes aegypti

Genetically engineered (GE) male Aedes aegypti of the OX5034 strain for use in mosquito control. Aedes aegypti is a known vector for human diseases associated with Zika, dengue, and chikungunya viruses. Oxitec’s novel approach to mosquito control uses the release of male OX5034 mosquitoes carrying a “female-specific self-limiting gene” to mate with wild females. When male OX5034 Aedes aegypti homozygous for the self-limiting gene (carrying two copies of the gene) are released into the environment and mate with wild Aedes aegypti females, their offspring inherit a single copy of the self-limiting gene (so are hemizygous). The self-limiting gene kills only female offspring (carrying one copy of the self-limiting gene), which die at early larval stages of development, while hemizygous males will survive to pass the OX5034 genes on to subsequent generations. Laboratory tests show that 100% of the resulting female offspring will die before reaching adulthood. Hence the OX5034 mosquito can be considered a sex- and species-specific larvicide targeting only female Aedes aegypti.

Expression of tTAV-OX5034 is regulated by tetracycline or one of its analogues. Tetracyclines bind to tTAV protein, preventing it from activating transcription. Thus, when either tetracycline or one of its analogues is absent from the OX5034 mosquito larval diet, tTAV-OX5034 protein causes lethality in females carrying at least one copy of the construct, including the progeny of mating between OX5034 homozygous males and wild Ae. aegypti females. Tetracycline Trans-Activator Variant (tTAV-OX5034) protein and the genetic material (from vector pOX5034) necessary to produce the protein in vivo

Figure: Schematic representation of the OX5034 female-lethal trait mediated through sex-specific tTAV-OX5034 expression. Top: In the absence of tetracyclines, basal expression of tTAV-OX5034 in female OX5034 Ae. Aegypti results in the production of the tTAV-OX5034 protein. The Aeadsx splicing module located at the 5’-end of the tTAV-OX5034 gene is alternately spliced in males and females, leading to the preferential expression of the fulllength tTAV-OX5034 mRNA isoform in females. Once the protein is translated it is cleaved by endogenous deubiquitinases at the UBQ-tTAV junction, releasing tTAV. tTAV then dimerizes (purple ovals). The positive feedback loop is closed when the VP16-domains of the tTAV protein bind to the tetO7 operator, which enhances the expression of the tTAV-OX5034 gene. Through this mechanism of overexpression, cellular functions are affected resulting in cell death in the developing larvae. Bottom: In the absence of tetracyclines, basal expression of tTAVOX5034 still occurs. Because tTAV preferentially binds to tetracycline than to tetO7, expression is not enhanced.

OX5034 is described as a species-specific female larvicide, or “male-selecting” larvicide, that results in all-male progeny in the absence of tetracycline in the larval diet due to a female-specific self-limiting gene. With continued field releases of OX5034 homozygous males, the    Ae. aegypti population is expected to progressively decline due to the reduced number of females emerging in the area. Specifically, when OX5034 homozygous males are released into the environment and mate with wild Ae. aegypti females, their offspring inherit a single copy of the self-limiting gene. The self-limiting gene kills only female offspring while hemizygous males survive to pass on the OX5034 self-limiting gene further. As the self-limiting gene is inherited in a Mendelian fashion, half of the offspring resulting from a mating between an OX5034 hemizygous male and a wild female would not inherit the self-limiting gene but would still inherit OX5034 strain genetics. This results in both male and female mosquitoes with OX5034 strain genetics.

Additionally, a recent paper examining the applicant’s 1st generation product, OX513A, found evidence of introgression after releases in Brazil of males containing the self-limiting tTAV gene (Evans et al. 2019). Although that paper investigated OX513A mosquitoes, the findings are relevant to the evaluation of OX5034 because the degree of introgression is likely to be significantly higher than that of the OX513A strain due to higher larval survival rates (approx. 5% in OX513A versus 50% in OX5034). Therefore, given that introgression of OX5034 strain genetics will occur during releases, it is pertinent to examine potential associated risks for humans and the environment. Traits associated with a disease vectoring species such as Ae. aegypti that may carry risk if introgressed into a wild population are likely to be linked to vectorial capacity, including vector competence, fecundity, and longevity.

The U.S. Food & Drug Administration regulates mosquito-related products that are intended to reduce the viral/pathogen load within a mosquito or are intended to prevent mosquito-borne disease in humans or animals (USFDA, 2017). EPA, on the other hand, regulates products intended to reduce the population of mosquitoes as pesticides, such as OX5034. Under the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA), EPA evaluates pesticide products to ensure that the products do not cause unreasonable adverse effects on humans or the environment. Consistent with the FIFRA standard, EPA is reviewing several factors that could contribute to the ability of the OX5034 mosquito to serve as a disease vector from the perspective that an increased ability to vector disease could result in a risk to humans or the environment.

Vectorial capacity is influenced by a number of traits impacted by gene-environment interactions and is confounded by both intrinsic and extrinsic variables. The applicant stated that during releases of OX5034 mosquitoes, the local population is expected to decline and therefore should have a reduced vectorial capacity due to decreased population density.

Environmental Protection Agency’s (EPA) decision to grant Oxitec an Experimental Use Permit (EUP) for piloting its 2nd generation Friendly Aedes aegypti mosquito technology, the result of an in-depth and rigorous scientific review process that included technical support from the U.S. Centers for Disease Control (CDC) and an expansive assessment of the technology and its safety relating to humans and the environment.

The EPA’s media statement below:

Ø  Oxitec to carry out demonstration projects with its safe, environmentally sustainable Aedes aegypti technology designed to control the mosquito that transmits dengue, Zika, chikungunya and yellow fever.

Ø  Approval adds to U.S. Food and Drug Administration’s (FDA)’s ‘Finding of No Significant Impact’ on human, animals or the environment for Oxitec’s mosquito technology (2016) and U.S. Department of Agriculture’s (USDA) approvals of field trials of two Oxitec agricultural pests.

Ø  U.S. Centres for Disease Control (CDC) supported EPA’s scientific review of application.

    Successful deployments of Oxitec insect technologies worldwide, and driven by a team of experts from the US, UK, Brazil, and a dozen other countries, Oxitec’s new Aedes aegypti technology represents a significant leap forward in efforts to provide municipalities and communities throughout the US with new, safe, sustainable and scalable tools to combat the growing threat posed by the invasive Aedes aegypti mosquito, which transmits devastating diseases such as dengue, Zika and chikungunya.

Oxitec has already completed successful deployments of this new Aedes aegypti technology in Brazil, demonstrating its ability to quickly and significantly suppress wild Aedes aegypti using easy-to-use, just-add-water deployment devices, thereby eliminating the need for costly production facilities and labor-intensive adult mosquito releases required by other insect-based technologies. This technology is designed to give governments and communities a powerful new solution that can scale effectively without the need for complex infrastructure and serve as a stand-alone solution or as a valuable component of integrated vector management programs.

EPA APPROVES EXPERIMENTAL USE PERMIT TO TEST INNOVATIVE BIOPESTICIDE TOOL TO BETTER PROTECT PUBLIC HEALTH

Environmental Protection Agency (EPA) has granted an experimental use permit (EUP) to Oxitec Ltd. to field test the use of genetically engineered Aedes aegypti mosquitoes as a way to reduce mosquito populations to protect public health from mosquito-borne illnesses.

During these field tests, Oxitec will release into the environment male mosquitoes genetically modified to carry a protein that will inhibit the survival of their female offspring when they mate with wild female mosquitoes. The male offspring will survive to become fully functional adults with the same genetic modification, providing multi-generational effectiveness that could ultimately lead to a reduction in Aedes aegypti mosquito populations in the release areas. EPA anticipates that this could be an effective tool to combat the spread of certain mosquito-borne diseases like the Zika virus in light of growing resistance to current insecticides.

            Male mosquitoes will be released into the environment and they do not bite people, they will not pose a risk to people. It is also anticipated that there would be no adverse effects to animals such as bats and fish in the environment.

            EPA has also maintained the right to cancel the EUP at any point during the 24-month period if unforeseen outcomes occur.

Similarities and differences between OX5034 and OX513A

Aedes aegypti mosquitoes Oxitec's l " generation self-limiting mosquito technology (OX513A), successfully deployed in multiple locations including in Brazil, the Cayman Islands and Panama, has been succeeded by the new 2nd generation self-limiting mosquito, OX5034. The OX5034 mosquito carries many of the key features of OX513A that made it a safe, effective control method for reducing Aedes aegypti mosquito populations. These include effective mosquito control, non-toxic and non-allergenic active and inert ingredients, a lack of direct effects on non-targeted species, and no long-term effects or chemical residues in the environment. OX5034 also has several additional features, including genetic sex-separation, which enables more cost-effective production and release of only male mosquitoes, and a brighter fluorescent marker, which enables field monitoring in all life stages of the mosquito. The key similarities and differences between OX513A and OX5034 are highlighted in the table below.

Technology Characteristics	1st Generation (OX513A)	2nd Generation (OX5034)
Effective mosquito control in field trials with built-in bio safety,	Yes; demonstrated in Cayman, Brazil & Panama	Yes; demonstrated in Brazil
No direct effect on non-targeted species	Yes	Yes
Non-toxic, non-allergenic active and inert ingredients	Yes (tTAY and DsRed2)	Yes (tTAY-OX5034 and DsRed2-0X5034)
No long-term effects on the environment; no chemical residues	Yes	Yes
Tetracycline used for rearing male mosquitoes for release	Yes	No
Genetic sex-separation; reduced costs and complexity	No; manual separation to >99.8% males	Yes; genetic separation to 100% males
Advanced fluorescent marker; visible in all post-egg life-stages	No; only visible in larvae	Yes; in larvae, pupae and adults
Multi-generational pest suppression; expected improvements in efficacy	Only one generation	Yes, multiple but limited number of generations

The DNA sequence of tTAV -OX5034 contains additional features (relative to OX513A) that enable its expression only in female mosquitoes, but the protein sequence is the same (99.4 % identity). The DNA sequence of DsRed2- OX5034 contains additional features that enable brighter expression in all mosquito life stages, but the fluorescent protein domain is the same as in OX513A (98.6% identity). All have the same non-toxic and non-allergenic safety profile.

Reference:

         EPA-HQ-OPP-2019-0274

         Beerntsen, B. T., A. A. James, and B. M. Christensen. 2000. Genetics of mosquito vector competence. Microbiology and Molecular Biology Reviews 64:115-137.