Bacillus Macerans Research Articles

Enzymatic Synthesis of α-Glucosyl-Baicalin through Transglucosylation via Cyclodextrin Glucanotransferase in Water.

Baicalin is a biologically active flavone glucuronide with poor water solubility that can be enhanced via glucosylation. In this study, the transglucosylation of baicalin was successfully achieved with CGTases from Thermoanaerobacter sp. and Bacillus macerans using α-cyclodextrin as a glucosyl donor. The synthesis of baicalin glucosides was optimized with CGTase from Thermoanaerobacter sp. Enzymatically modified baicalin derivatives were α-glucosylated with 1 to 17 glucose moieties. The two main glucosides were identified as Baicalein-7-O-α-D-Glucuronidyl-(1→4')-O-α-D-Glucopyranoside (BG1) and Baicalein-7-O-α-D-Glucuronidyl-(1→4')-O-α-D-Maltoside (BG2), thereby confirming recent findings reporting that glucuronyl groups are acceptors of this CGTase. Optimized conditions allowed for the attainment of yields above 85% (with a total glucoside content higher than 30 mM). BG1 and BG2 were purified via centrifugal partition chromatography after an enrichment through deglucosylation with amyloglucosidase. Transglucosylation increased the water solubility of BG1 by a factor of 188 in comparison to that of baicalin (molar concentrations), while the same value for BG2 was increased by a factor of 320. Finally, BG1 and BG2 were evaluated using antioxidant and anti-glycation assays. Both glucosides presented antioxidant and anti-glycation properties in the same order of magnitude as that of baicalin, thereby indicating their potential biological activity.

Detection of Enterotoxin Genes in Bacillus species Isolated from Cassava Processing Environment in Nigeria

Introduction: The health challenges associated with cassava products as a common staple food for approximately 70 % of Africans and part of Asia pose a looming danger due to Bacillus enterotoxins’ presence in the processing environment. Objective: This study investigated the presence of enterotoxigenic genes, namely, Bacillus cereus enterotoxin T (bceT), hemolysin bl (hblC, hblD), and non-haemolytic enterotoxin (nheA, nheB, and nheC) from Bacillus species isolated from soil of cassava processing environment. Methods: Soil samples from 20 cassava processing sites in Ile-Ife and Modakeke, Nigeria, were collected and cultured on nutrient agar at 37ºC for 24 hours. Colonies phenotypically identified as Bacillus were identified using Bacillus-specific 16S rRNA-targeted PCR technique. Screened Bacillus spp were assessed for the presence of enterotoxigenic genes using PCR with previously reported primers. Results: A total of 100 Bacillus isolates were selected from this study, with Bacillus macerans (33 %) showing the highest frequency of occurrence among the identified species, however, 74 isolates were molecularly confirmed as Bacillus. Amongst the 74 molecularly confirmed Bacillus isolates, 28 (37.84 %), 35 (47.30 %), and 37 (50 %) had nhe, hbl, and bceT genes, respectively. Investigation showed that 42 (56.76 %) of the Bacillus species encoded at least one of the screened enterotoxin genes. Conclusion: The presence of these 3 sets of enterotoxin genes in Bacillus isolated from cassava processing sites calls for immediate attention as they could be pivotal in the release of toxins in cassava products, causing lethal effects via consumption. This study demonstrates the possibility of foodborne disease outbreaks in Bacillus toxin-laden cassava products processed under unhygienic conditions.

Effects of Fizzy Drinks on Blood Sugar Level, Sputum and Enteric Bacterial Populations in Healthy Human Beings

Fizzy drinks are non-alcoholic beverages typically containing water, sweetener, carbon dioxide, acidulates, flavourings, colourings, chemical preservatives, antioxidants, and/or foaming agents. They are usually characterized by a high C/N ratio and low pH, which allows the growth of specific microbial groups while limiting others. Blood sugar level, sputum, and faecal samples were collected from twenty healthy students (pre and post-fasting) and analyzed microbiologically to determine the effect of the consumption of fizzy drinks on the body’s enteric bacteria population. Samples were processed and cultured using pour plate and streak plate techniques in three selective media consisting of Maconkey agar, Salmonella Shigella agar, and Eosin Methylene Blue agar. Differentiation and isolation of various isolates were based on gram-staining technique after culturing for 24 hours at 37ºC and biochemical reactions using MICROBACT 12A/12B and 24E identification kits. Following consumption of fizzy drinks 35cl for females and 60cl for males, results show there was no significant difference between pre and post fasting blood sugar levels (84.2 and 85.7) and (90.7 and 118.1) mg/dl in males and females respectively. In females, post-consumption blood sugar level was higher (86.6 to 82.0) mg/dl in the Bigi Lemon group compared with lower post-consumption blood sugar level (84.8 to 86.4) mg/dl in Bigi Orange group. Among males, post-consumption blood sugar level was higher in both Coke and Fanta groups (93.6 to 123.8 and 87.8 to 112.4) mg/dl respectively. The average oral microbial load from sputum samples reduced in both males and females (1.90 to 0.93× 105) and (1.52 to 0.44× 105) cfu/g respectively post consumption. Post consumption, sixty-three bacterial isolates comprising eight organisms in sputum with the following percentage prevalence were detected, namely: Micrococcus varians (18.18%), Staphylococcus saprophyticus (3.030%), Micrococcus acidophilus (21.212%), Bacillus macerans (18.18%), Bacillus cereus (9.09%), Staphylococcus aureus (9.09%), Streptococcus pyogenes (3.030%) and Bacillus subtilis (18.18%), while in faecal samples with the following bacteria with the following percentage prevalence were isolated: Staphylococcus aureus (7.94%), Escherichia coli (25.40%), Klebsiella (20.63%), Shigella (17.46%) and Salmonella (28.57%).

Effect of plant growth promoting bacteria on the phenology of the Amarilla maranganí quinoa cultivar

Bacteria associated with plant roots can generate different responses on the growth and development of plants which affect yield. For this reason, a test was conducted and aimed at evaluating the effects of plant growth promoting bacteria’s inoculation on the yield of the Amarilla Maranganí quinoa cultivar, using bacterial strains such as Bacillus macerans, Bacillus laterosporus, Bacillus licheniformis, Bacillus cereus, Actinobacillus, Pseudomonas aeruginosa, Consortia (a combination of the characterized bacteria), and DIPEL (Bacillus thuringensis var. Kurstaki). The study included the evaluation of the length of the plants and panicles as well as the number of inflorescences and seed production using a completely randomized experimental design. The results showed that the microorganisms had a large impact on plant growth. Actinobacillus increased the number of panicles while P. aeruginosa improved grain production. These results allowed us to confirm that the use of microorganisms favors the growth parameters of quinoa and allowed us to recognize the biological potential of growth promoting bacteria in this crop under conditions of poor water and nutrient availability.

Microbial activities and physicochemical properties of pesticide treated soils and waters

This study determined the concentration of the pesticides contaminating the soil and water, and the effect of the pesticides on microbial activity and physicochemical properties. Nutrient agar was used for the enumeration of total heterotrophic bacteria by the pour plate method. Enumeration of fungi was done with Potato Dextrose Agar. Soil CO2-evolution was estimated every 5-days for 25 days. Total nitrogen was determined using macro-Kjeldhal distillation method. Available phosphorus was analyzed using Bray No. 1 method. Dehydrogenase activity in samples was assayed with 2,3,5-triphenyl tetrazolium chloride solution. COD was determined by the method of Ademoroti. DO was determined by Winkler’s method. Bacillus subtillis, Bacillus macerans, Pseudomonas aeruginosa, Psedomonas putida and A. niger were of common occurrence in all soil samples. There were significant changes (P≤0.05) in the microbial activities and available phosphorus, total nitrogen and pesticide concentration of the polluted soil and water samples. The BOD ranged from 15.837±0.187 to 20.853±0.254 mg/L. The DO, COD and BOD of the control water samples were significantly (P≤0.05) higher than the values obtained at the point of pollution. This study indicated the extent of microbial and pesticide pollution; further addition of wastes may deteriorate the existing hygienic quality of water in these locations.

Enzymatic Activity of Rhizobacillus Isolated from Tomato Rhizosphere

Aim: The aim of this study was to isolate Rhizobacillus from tomato rhizosphere and its screening for the production of hydrolytic enzymes to be used as a biocontrol agent.
 Place of Study: The study was carried out in the Department of Microbiology, Faculty of Science, Ekiti State University, Ado Ekiti, Nigeria in August 2018.
 Methodology: Isolation was of Rhizobacillus carried out from rhizospheric soil of tomato plant at agro-zone along Afao road Ado Ekiti using pour plate method. Enzyme assay was carried out on the bacterial isolates, to examine their ability to produce hydrolytic enzyme required for biocontrol of phytopathogenic fungi. Isolates were tentatively identified with the help of Bergy’s Manual of Systemic Bacteriology.
 Results: Ten strains were tentatively identified as B. brevis, B. circulans BC1, B. macquariensis BM1, B. macquariensis BM2, B. macerans, B. macquarensis BM3, B. alcalophilus B. macerans BC11, B. circulans BC3 and B. macerans BC9. All the Isolates demonstrated the ability to produce hydrolytic enzymes with the highest activity recorded in Bacillus macquariensis BM2 (60.28 µmol) for chitinase, Bacillus macerans BC9 (11.14 µmol) for Protease, Bacillus macquariensis BM2 (150.00 µmol) for Glucanase, and Bacillus circulans BC1 (46.45 µmol) for cellulase respectively. In conclusion the Bacillus strains isolated from rhizosphere are promising and could be used in bioprocessing technology to produce hydrolytic enzymes for the purpose of biocontrol in management of phytopathogenic fungi.

Chilled storage of banana shrimp ( Fenneropenaeus merguiensis ) spermatophores with supplementation of moringa ( Moringa oleifera Lam.) extract

This study was designed to optimize the chilled storage method for banana shrimp (Fenneropenaeus merguiensis) spermatophores and evaluate the potential of moringa (Moringa oleifera Lam.) extract on the reduction in bacterial contaminants during spermatophore preservation due to the uncertainty of the broodstock. Spermatophores were suspended in five extenders: mineral oil, Ringer's solution, phosphate buffer, calcium-free saline and 0.8% NaCl and stored at 2–4°C. During a 28-day storage, spermatophores stored in mineral oil showed the highest sperm viability (89.1%) and intact morphology with a slight formation of hardened adhesive matrices. The effect of moringa extract was investigated on chilled spermatophores. Spermatophores were suspended in mineral oil (the control) and mineral oil containing either penicillin–streptomycin (0.1%) or moringa extract (0.1 mg/ml) during a 28-day storage. Supplementation of moringa extract resulted in a significant increase (p < .05) in sperm survival, compared to the control, and a complete elimination of culturable Vibrio (Vibrio alginolyticus, Vibrio mimicus and Vibrio furnissii), Staphylococcus kloosii, Bacillus macerans, Listeria ivanovii, Corynebacterium paurometabolum and Corynebacterium bovis, in chilled spermatophores. Chilled storage of spermatophores in mineral oil containing moringa extract was a promising technique due to the inhibition of shrimp and human pathogens without the spermicidal effect on banana shrimp sperm.

Karakterisasi Enzim Komersial Siklodekstrin Glukanotransferase

The objective of this study is to investigate the characteristic of commercial enzyme Cyclodextrin Glucanotrasferase (CGTase) from Bacillus macerans. The CGTase was purified by dialysis, gel fitration and ion exchange chromatography. Study on Characterization of the enzyme showed that the hydrolytic activity of CGTase was 480 U/mg, the optimum tempetature and pH for enzyme reaction were 450C to 550C and pH 5.0 to 8.0, respectively. The CGTase was relatively stable after heating at 550C for 10 minutes, and maintained its activity at the pH 5.0 to 9.0. The enzyme activity was inhibited by the presence of 1 mM metal ions and cause CGTase lost approximately 40% of its activity. Among the metal ions it was found that Cu2+ was the strongest inhibitor, with presence of 1mM Cu2+ the residual activity of CGTase was 24.4%. Results of purification showed that Specific activities of the enzyme during purification were 269 U/mg (crude enzyme); 955 U/mg (dialysis); 481 U/mg (gel fitrations); and 544 U/mg (ion exchange chromatography).

Rhizobacteria Suppress Fusarium wilt and Early Blight Diseases in Tomato Grown with Organic Fertilizers

Due to the established toxic effects of agrochemical accumulation in humans, there is an increasing demand for organic agricultural production in Nigeria. The production of highly nutritious and daily consumed crops like tomato through organic farming (using biosupplements) would go a long way in reducing the risks associated with the consumption of inorganic pesticides and fertilizers. In order to investigate the effects of rhizobacterial biosupplement on the resistance and yield of tomato grown with organic fertilizers, the predominant rhizosphere bacteria associated with healthy tomato isolated in this study (Bacillus thuringiensis, Pseudomonas aeruginosa, Bacillus subtilis, Bacillus macerans and Bacillus cereus) were added as a consortium to improve the availability of organic nutrients to plants. Performance measures including the numbers of fruit, branches, leaves, plant height, days to first flowering and days to 50% flowering at 20.00, 17.67, 176.33, 73.33 cm, 70.43 and 78.00 were all better (higher or lower) in treated tomato plants than untreated set. A significant reduction in percentage prevalence was recorded for Fusarium wilt, as well as Early blight diseases on treated plants (seed treatment with rhizobacterial consortium) compared to plants grown from untreated seeds. However, seed treatment appeared to be less effective in the treatment of Bacterial wilt disease of tomato, with percentage prevalence of 41.70 and 42.90 recorded for treated and untreated plants at nine weeks after planting respectively. It could be concluded that the application of rhizobacterial consortium (as seed treatment) improved the yield and resistance of tomato to Fusarium wilt and Early blight diseases caused by Fusarium oxysporum and Alternaria solani respectively.

Effects of Difference Processing Methods on Microbiological Properties an African Oil Bean Product

The prepared seed slices of African oil bean (pentaclthra macrophylla Benth) were subjected to different fermentations periods and dried using different drying method to produce “Ugba”. Slices were milled to obtain flour. The flour from different ‘Ugba’ samples were analysed for microbial load. There were no significant difference p> 0.05) in the sizes of ugba. The micro organisms identified by characterization in the “ugba” samples after drying were Bacillus, Lactobacillus, staphylococcus, micrococcus Enterbacterium. Only the Bacillus were found to ferment the African oil bean seeds to “ugba”. They were also the predominant micro organisms present. After experiment of total microbial population density of the species of Bacillus found to be responsible for the fermentation of African oil bean seeds to “ugba” were identified as Bacillus Coagulans, Bacillus macerans, Bacillus megaterium, Bacillus pumilis, and Bacillus subtilis.

Heavy metal levels, physicochemical properties and microbial diversity of soil matrix from university solid waste collection sites in Benin City, Nigeria

This study was carried out to assess the microbial, physicochemical and heavy metal characteristics of soil samples from five different waste collection sites within the University of Benin, Benin City and evaluated using standard analytical and classical microbiological methods. The heavy metal concentration includes Zn (4.45±0.00 - 5.76±0.02 mg g−l); Cd (1.59±0.00 - 2.54±0.00 mg g−l); and Fe (1.02±0.02 - 1.07±0.00 mg g−l). The physicochemical properties include pH (4.91±0.01 - 5.82±0.04); TOC (6.49±0.01 - 7.65±0.02 %); NO2 − (29.32±0.07 - 32.81±0.11 mg g−l); and SO4 2− (47.30±0.12 - 63.25±0.04 mg g−l). The mean of culturable heterotrophic and coliform bacteria ranged from 4.03×107 ± 0.35 - 4.51×108 ± 0.12 CFU/g and 1.02×104 ± 0.12 - 3.10×105 ± 0.02 CFU/g respectively. At p-value &lt; 0.01 level EC significantly correlates total heterotrophic bacteria (r= 0.971); coliform bacteria significantly correlate NO3 − (r= 0.989); while clay significantly but negatively correlates coliform bacteria (r= -0.989). Some of the bacteria isolated and identified from the waste collection sites include Klebsiella oxytoca, Enterobacter aerogenes, Staphylococcus aureus, Pseudomonas putida, and Bacillus macerans. Findings from this study reveal that the municipal solid waste on the collection sites has impacts on the indicator variables of the resident soil as well as serving as breeding sites for pathogenic organisms.Keywords: solid waste, environmental hazard, soil quality, pathogens

English

The aim of the study was to investigate the bioethanol production potentials by indigenous bacterial isolates screened for amylolytic and cellulolytic activities. Cassava peels were obtained from local ‘garri’ producers, while corn grains and corn cobs were gotten from retailers within the Erinfun farm settlement along Afe Babalola University Road, Ado-Ekiti, Ekiti State, Nigeria on June 4, 2015. The substrates (corn flour, corn cob and cassava peels) were sundried for 5 days and ground into fine powder using a hammer mill and analyzed for proximate nutrient composition and reconstituted to a 5% concentration in water before fermentation. The fermentation was set up for 20 days using single cultures of bacteria and co-cultures of bacteria and yeast selectively isolated and screened for amylolytic and cellulolytic activities. Parameters such as pH, total titratable acidity, reducing sugar and optical density were taken at intervals of 5 days and ethanol production was analyzed at the end of fermentation. Three bacterial isolates (Bacillus macerans, Bacillus subtilis and Micrococcus varians) yielded ethanol in all the feed stocks. The highest percentage ethanol yield was observed in the fermentation of corn flour and corn cobs with B. macerans which were 3.6 ± 0.009 and 3.5 ± 0.009, respectively. There was reduction in the pH and total titratable acidity and increase in the reducing sugar content and optical density. B. macerans exhibited the highest average ethanol production (3.5±0.07%). A proximate analysis of the feed stocks showed presence of nitrogen, protein, fat, carbohydrate and ash. This study investigated the potentials of wastes (cassava peels and corn cob) used as feed stocks for bio-ethanol production, in substantially replacing major food crops (corn) as a case study. Key words: Fermentation, amylolytic activity, cellulolytic activity, corn flour, corn cob, cassava peels, feed stocks.

Glucosylation of flavonol and flavanones by Bacillus cyclodextrin glucosyltransferase to enhance their solubility and stability.

Enzymatically modified isoquercitrin (EMIQ), oligoglucosyl naringenin-7-(glucose [G]), and oligoglucosyl hesperetin (H)-7-G were produced via oligoglucosylation of quercetin-3-glucose, naringenin-7-G (prunin), and H-7-G, respectively, by cyclodextrin glucosyltransferase from Bacillus macerans. The aim was to explore the oligoglucosylation and the resulting changes in physicochemical properties. Water solubility of EMIQ, oligoglucosyl prunin, and oligoglucosyl H-7-G enormously increased in comparison with that of their aglycones. Glycosylation of an aglycone generally enhances its solubility. Resistance of the aglycones to oxidative degradation by the Cu2+ ion was strongly increased by the oligoglucosylation. This is probably because oligoglucosylation may protect sensitive parts of an aglycones molecule from the Cu2+ oxidation. Only EMIQ maintained its structure during thermal treatment much longer than quercetin did. Degradation of flavonoid aglycones by ultraviolet light C irradiation at 254nm was not affected, and their antioxidant activities gradually decreased with the greater extent of oligoglucosylation.

Characterization and activity of antimicrobial polypeptide of Bacillus spp from wastelands of Kathmandu valley

Background: Bacillus genus have been found to produce antimicrobial polypeptides that have a remarkable capability to combat the current increasing problem of antibiotic resistance. The aim of this cross sectional study was to determine the proportion and pattern of distribution of antibiotic producing and non-producing species of Bacillus in soil and also to analyse the activity of the antibiotic producers. Methods: A total of 40 soil samples were collected from the wastelands of Kathmandu Valley and 121 isolates were studied from them. They were identified according to Bergey’s Manual. The antibiotic were extracted and the activity was analysed by agar- well diffusion method against the test organisms Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853. Result: Bacillus subtilis species were found to be in highest number (17.3%) and Bacillus macerans (0.82%) in lowest number. 18.33% of Bacillus isolates were found to produce antibiotics. The highest number of antibiotic producing isolate was B. subtilis (40.09%) and the least was B. circulans (4.54%). The number of antibiotic producing bacteria were not found to be affected by moisture content of soil and pH change. Among the antibiotic producers, 63.63% produced antibiotic against Gram positive bacteria, 27.27% against Gram negative bacteria and B. alvei (9.09%) had a broad spectrum activity. Some colonies were even found to produce antibiotic with a greater potential than the conventional antibiotics. Conclusion: Based on property of soil, moist-neutral soil had the highest number of bacilli isolates and dry-acidic and moist-alkaline had least number of isolates. DOI: 10.21276/AABS.2017.1316

Potential Production of Tannin Acyle Hydrolase by Enterococcus caseliflavus Using Green Tea

Eleven bacterial strains were isolated from the tannery soil sample on tannic acid agar medium by dilution plate method. They were identified as Enterococcus caseliflavus, Lactobacillus fermenti, Lactobacillus delbaecki, Lactobacillus bifidus, Bacillus lentus, Bacillus macerans, Bacillus bdius, Bacillus brevis, Enterococcu mundtii, Enterococcus hira, and Streptococcus mitis. Liquid State Fermentation technique using Green tea (GT) as tannin rich substrate was used as selective media in the survey. Enterococcus caseliflavus showed the most active strain in tannin acyl hydrolase production on green tea. Tannin acyl hydrolase enzyme (TAH) activity after optimization recorded 2.86 fold increase compared with the activity before optimization; Plackett–Burman design was applied for the screening of 8 variables on the production of tannin acyl hydrolase using green tea as a substrate. The effect of the tested variables was screened at the probability (P) level of 0.05. The Significant variables effect of Additive glucose (D) is the most significant factor affecting TAH production followed by, Initial pH(B), NH4CL (F),and Incubating temperature(A). The analysis of variance of models after the exclusion of insignificant coefficients showed that the coefficient of determination (R2) was 0.999705for tannin acyl hydrolase.

Variation in the content of total phenolics, anthocyanins and antimicrobial effects in two fractions of blueberries different cultivars

Abstract Two fractions (pomace and juice) of blueberries of seven commercial cultivars growing in the same plantation were analysed for the content of total phenolics (TPC), total anthocyanins (TAC) and effects on food pathogens over different harvesting years. TPC in pomace did not differ significantly between years only in ‘Gretha’ and ‘Northblue’ cultivars; they accumulated stable content of phenolics. The variation in TAC in pomace across seasons was 2–5 times higher than that in TPC. The variations in TPC and TAC in juice across harvesting years were lower than in pomace, but both TPC and TAC in this fraction also differed significantly (p &lt; 0.05) between years in all studied cultivars. The activity of juice and pomace of cultivars against food pathogens was mostly stable and did not show significant differences between harvesting years; the significant correlations were not established between antimicrobial activity of both berries fractions and TPC and TAC in all investigated cultivars. Bacteria were the most susceptible to blueberry juice with Micrococcus spp., Bacillus macerans and Escherichia coli being the most sensitive species. The evaluation of antifungal effect shows that only P. chrysogenum was sensitive to the juice of blueberries, while Aspergillus niger, Cladosporium sphaerosphermum and Penicillium chrysogenum showed resistance to the tested blueberries juice and pomace extracts.

Enhanced exo-inulinase activity and stability by fusion of an inulin-binding module.

In this study, an inulin-binding module from Bacillus macerans was successfully fused to an exo-inulinase from Kluyveromyces marxianus, creating a hybrid functional enzyme. The recombinant exo-inulinase (rINU), the hybrid enzyme (rINUIBM), and the recombinant inulin-binding module (rIBM) were, respectively, heterologously expressed and biochemically characterized. It was found that both the inulinase activity and the catalytic efficiency (k cat/K m(app)) of the rINUIBM were considerably higher than those of rINU. Though the rINU and the rINUIBM shared the same optimum pH of 4.5, the optimum temperature of the rINUIBM (60°C) was 5°C higher than that of the rINU. Notably, the fused IBM significantly enhanced both the pH stability and the thermostability of the rINUIBM, suggesting that the rINUIBM obtained would have more extensive potential applications. Furthermore, the fusion of the IBM could substantially improve the inulin-binding capability of the rINUIBM, which was consistent with the determination of the K m(app). This meant that the fused IBM could play a critical role in the recognition of polysaccharides and enhanced the hydrolase activity of the associated inulinase by increasing enzyme-substrate proximity. Besides, the extra supplement of the independent non-catalytic rIBM could also improve the inulinase activity of the rINU. However, this improvement was much better in case of the fusion. Consequently, the IBM could be designated as a multifunctional domain that was responsible for the activity enhancement, the stabilization, and the substrate binding of the rINUIBM. All these features obtained in this study make the rINUIBM become an attractive candidate for an efficient inulin hydrolysis.

The emulsifying effect of biosurfactants produced by food spoilage organisms in Nigeria

Food spoilage organisms were isolated using standard procedures on Nutrient Agar, Cetrimide Agar and Pseudomonas Agar Base (supplemented with CFC). The samples were categorized as animal products (raw fish, egg, raw chicken, corned beef, pasteurized milk) and plant products (vegetable salad, water leaf (Talinium triangulare), boiled rice, tomatoes and pumpkin leaf (Teifairia occidentalis).They were characterised as Pseudomonas putida, Pseudomonas aeruginosa, Pseudomonas stutzeri, Burkholderia pseudomallei, Serratia rubidaea, Corynebacterium pilosum, Bacillus subtilis, Bacillus mycoides, Bacillus laterosporus, Bacillus laterosporus, Serratia marcescens, Bacillus cereus, Bacillus macerans, Alcaligenes faecalis and Alcaligenes eutrophus. Preliminary screening for biosurfactant production was done using red blood haemolysis test and confirmed by slide test, drop collapse and oil spreading assay. The biosurfactant produced was purified using acetone and the composition determined initially using Molisch’s test, thin layer chromatography and gas chromatography mass spectrometry. The components were found to be ethanol, amino acids, butoxyacetic acid, hexadecanoic acid, oleic acid, lauryl peroxide, octadecanoic acid and phthalic acid. The producing organisms grew readily on several hydrocarbons such as crude oil, diesel oil and aviation fuel when used as sole carbon sources. The purified biosurfactants produced were able to cause emulsification of kerosene (19.71-27.14%) as well as vegetable oil (16.91-28.12%) based on the emulsification index. This result suggests that the isolates can be an asset and further work can exploit their optimal potential in industries.

The emulsifying effect of biosurfactants produced by food spoilage organisms in Nigeria

Food spoilage organisms were isolated using standard procedures on Nutrient Agar, Cetrimide Agar and Pseudomonas Agar Base (supplemented with CFC). The samples were categorized as animal products (raw fish, egg, raw chicken, corned beef, pasteurized milk) and plant products (vegetable salad, water leaf ( Talinium triangulare ), boiled rice, tomatoes and pumpkin leaf ( Teifairia occidentalis ).They were characterised as Pseudomonas putida, Pseudomonas aeruginosa, Pseudomonas stutzeri, Burkholderia pseudomallei, Serratia rubidaea, Corynebacterium pilosum, Bacillus subtilis, Bacillus mycoides , Bacillus laterosporus, Bacillus laterosporus , Serratia marcescens, Bacillus cereus, Bacillus macerans, Alcaligenes faecalis and Alcaligenes eutrophus. Preliminary screening for biosurfactant production was done using red blood haemolysis test and confirmed by slide test, drop collapse and oil spreading assay. The biosurfactant produced was purified using acetone and the composition determined initially using Molisch’s test, thin layer chromatography and gas chromatography mass spectrometry. The components were found to be ethanol, amino acids, butoxyacetic acid, hexadecanoic acid, oleic acid, lauryl peroxide, octadecanoic acid and phthalic acid. The producing organisms grew readily on several hydrocarbons such as crude oil, diesel oil and aviation fuel when used as sole carbon sources. The purified biosurfactants produced were able to cause emulsification of kerosene (19.71-27.14%) as well as vegetable oil (16.91-28.12%) based on the emulsification index. This result suggests that the isolates can be an asset and further work can exploit their optimal potential in industries.

Statistical optimization of cyclodextrin glycosyltransferase (CGTase) production from Bacillus macerans in batch cultivation and its purification

Cyclodextrin glycosyltransferase (CGTase) catalyzes the formation of Cyclodextrins from starch by an intramolecular transglycosylation reaction. In the present study, the CGTase enzyme was produced from Bacillus macerans NCIM 2131, using shake flask fermentation. Soluble starch and yeast extract were screened as the best carbon and nitrogen source at an individual factor level for enhancing CGTase activity. Similarly, ferrous ion and arginine were found to activate CGTase production in comparison to various other trace metals and amino acids tested. The synergistic effect of individual parameters of CGTase activity and process optimization of cultural condition was performed by response surface methodology (RSM). The optimized media comprised 24 g/L soluble starch; 32.5 g/L ferrous ion, and 15.0 g/L arginine with CGTase activity of 24.23 IU/mL. The final CGTase activity was very close to the predicted value of 24.82 IU/mL with 97.0% validation. Shake flask optimized conditions were further scaled up to 7.5 L fermenter (working volume: 3.0 L) which gave 2.6 folds (64.3 IU/mL) increase in enzyme activity. The enzyme was partially purified by ammonium sulfate precipitation and scanning electronic microscopy (SEM) was used to study the qualitative properties of produced enzyme.