Bacillus Cultures Research Articles

An extremely thermostable maltogenic amylase from Staphylothermus marinus: Bacillus expression of the gene and its application in genistin glycosylation

The most extremely thermostable maltogenic amylase (SMMA) from archaeon Staphylothermus marinus has many potential applications in food processing. To ensure safety of microbial origin, a recombinant plasmid containing the enzymic gene and a constitutive promoter AmyR2 was constructed, and then transformed into a GRAS microorganism Bacillus subtilis. The purified SMMA from the liquid cultures of Bacillus has a specific activity of 66.96U/mg, two times more than that from Escherichia coli. SMMA was further employed to catalyze the genistion glycosylation using γ-CD as both glucosyl donors and solubilizer. Glycosylated genistins with one to four additional α-glucosyls and a molar percentage of 69.87% in genistin reaction mixture were identified and quantified by HPLC–UV–MS. The glycosylated genistins at 0.2–1.2mM showed an enhanced DPPH free radical scavenging capacity. To our knowledge, this is the first report on the Bacillus expression of archaeal maltogenic amylase.

English

INTRODUCTION : Pleural effusion is a collection of fluid in the Pleural space. It is not a disease but rather a complication of an underlying illness. Effusion can occur for a variety of reasons. Common classification systems divide pleural effusions into two categories of (1) Transudative pleural effusions and (2) Exudative pleural effusions. Determining the cause of a pleural effusion is greatly facilitated by analysis of the pleural fluid. Thoracentesis is a simple bedside procedure that permits fluid to be rapidly sampled, visualized, examined microscopically, and quantified. A systematic approach to analysis of the fluid in conjunction with the clinical presentation should allow the clinician to diagnose the cause of an effusion. • A definitive diagnosis is provided by the finding of malignant cells or specific organisms in the pleural fluid, can be established in approximately 25 percent of patients. • Pleural effusion remains undiagnosed after routine tests in pleural fluid in many patients. so, we need a simple and safe investigative tool to evaluate undiagnosed effusion. This study is designed to diagnose the cases of undiagnosed effusions by a simple and safe investigative tool. Pleural fluid accumulates when pleural fluid formation exceeds pleural fluid absorption. Normally fluid enters the pleural space from the capillaries in the parietal pleura and is removed via the lymphatics situated in the parietal pleura. Fluid can also enter the pleural space from the interstitial spaces of the lung via the visceral pleura or from the peritoneal cavity via small holes in the diaphragm. The lymphatics have the capacity to absorb 20 times more fluid than is normally formed. Accordingly, a pleural effusion may develop when there is excess pleural fluid formation (from the interstitial spaces of the lung, the parietal pleura, or the peritoneal cavity) or when there is decreased fluid removal by the lymphatics. AIMS AND OBJECTIVES : 1. To evaluate the role of closed Pleural biopsy in diagnosing exudative effusions not diagnosed by Pleural fluid analysis. 2. To compare the yield of each test (Histopathological examination, Reverse Transcriptase Polymerase Chain Reaction and culture for Tuberculosis by BACTEC) in Pleural biopsy specimens of undiagnosed exudative Effusions. MATERIALS AND METHODS : STUDY DESIGN : This is a Prospective (Observational) study designed to evaluate the role of closed pleural biopsy in undiagnosed exudative Pleural effusion. STUDY CENTER : The study was done at the Department of Thoracic Medicine – Government General Hospital, Chennai. STUDY DURATION : January 2010 to June 2010. STUDY POPULATION : Patients with exudative pleural effusion remain undiagnosed after pleural fluid analysis. Proforma was designed and ethical clearance was obtained. A written informed consent was obtained from all the patients included in the study after explaining in detail the nature and purpose of the study. INCLUSION CRITERIA : Exudative effusion which is negative for Malignant cells, Acid Fast Bacillus, Gram stain and Non Tuberculous culture in Pleural fluid. EXCLUSION CRITERIA : • Exudative effusion positive for Malignant cells, • Exudative effusion positive for Tuberculosis in Pleural fluid Smear, • Exudative effusion positive for Gram stain or Non-Tuberculous Culture, • Parenchymal lesion in the X-ray suggestive of Tuberculosis or Malignancy or parapneumonic effusion, • Uncooperative patients, • Coagulation disorders, • Dry pleural tapping, • Empyema, • Uremia. CONCLUSION : Combination of Histopathological examination, BACTEC culture and Reverse Transcriptase Polymerase Chain Reaction in closed Pleural biopsy has a greater diagnostic yield in diagnosing exudative effusions not diagnosed by Pleural fluid analysis. • Histopathological examination diagnosed 67% of Tuberculous effusion. • Reverse Transcriptase Polymerase Chain Reaction diagnosed 26.1% of Tuberculous effusion. • BACTEC diagnosed 11.8% of Tuberculous effusion. • Histopathological examination diagnosed 70% of Malignant effusion. • 82.3% of Tuberculous cases were diagnosed by combining all three tests. • 82.3% of Tuberculous cases were diagnosed by combining Histopathological examination and Reverse Transcriptase Polymerase Chain Reaction. • Pleural biopsy diagnosed 79% of undiagnosed effusion. • Closed Pleural Biopsy can be used as a easy, quick, cost effective and relatively safe method to diagnose an exudative effusion not diagnosed by pleural fluid analysis.

Bioelectricity generation and treatment of petroleum refinery effluent by <i>Bacillus cereus</i> and <i>Clostridium butyricum</i> using microbial fuel cell technology

Microbial fuel cells (MFCs) being an emerging technology have been the research focus of increasing interest due to their sustainable capacity for wastewater treatment together with electricity generation. This study investigated the potential use of pure culture Bacillus cereus and Clostridium butyricum as inoculums in MFCs for simultaneous bioelectricity generation and treatment of petroleum refinery effluent. Double-chambered MFCs was used for the study and operated over four-batch cycles for 30 cumulative days but with different external resistances. The influent concentrations of chemical oxygen demand (COD) and total organic compound (TOC) in the petroleum refinery effluent was 970 mg/l (ppm) and 156 g/l, respectively. Experimental results indicated that the MFCs with the use of Bacillus cereus as biocatalyst achieved its maximum COD removal, TOC degradation and coulombic efficiencies of 70%, 88.7% and 19.21%, respectively; while with the use of Clostridium butyricum, it achieved the highest COD removal, TOC degradation and coulombic efficiencies of 54.2%, 68.7% and 17.84%, respectively. A maximum voltage of 450 mV and highest power density of 17066.67 mW/m 2 with a maximum current density of 1.270 mA/m 2 was obtained in regard to the external resistor of 1000 Ω using Bacillus cereus as biocatalyst. Similarly, using Clostridium butyricum as biocatalyst the maximum voltage of 370 mV and highest power density of 8816.17mW/m 2 with a maximum current density of 0.913 mA/m 2 was achieved. The study demonstrated that both Bacillus cereus and Clostridium butyricum has strong potentials to be used as inoculums for simultaneous bioelectricity generation and treatment of petroleum refinery effluent in MFCs. http://dx.doi.org/10.4314/njt.v36i2. 30

Rapid production of tetrodotoxin-like compounds during sporulation in a marine isolate Bacillus sp. 1839

The marine Bacillus sp. strain 1839 produces tetrodotoxin-like (TTX-like) compounds during sporulation. In this study, the environmental signals that regulate spore formation and the synthesis of TTX-like substances were examined. The main sporulation trigger for Bacillus sp. 1839 was changes in environmental osmolality. Confocal laser scanning (CLSM) and transmission electron microscopy with anti-TTX anti-bodies were used to locate TTX-like compounds in a sporulated culture of Bacillus sp. 1839. Based on CLSM studies, the toxin was synthesized within a few minutes after the induction of sporulation, and the fluorescence signal reached the maximum intensity in 60 min. Immunoelectron microscopy enabled the detection of TTX-positive structures in spores with unformed cores. The results obtained in this study provide an important basis for the development of biotechnological production methods for the highly effective anesthetic drug.

An improved protocol for harvesting Bacillus subtilis colony biofilms

Bacterial biofilms cause severe problems in medicine and industry due to the high resistance to disinfectants and environmental stress of organisms within biofilms. Addressing challenges caused by biofilms requires full understanding of the underlying mechanisms for bacterial resistance and survival in biofilms. However, such work is hampered by a relative lack of systems for biofilm cultivation that are practical and reproducible. To address this problem, we developed a readily applicable method to culture Bacillus subtilis biofilms on a membrane filter. The method results in biofilms with highly reproducible characteristics, and which can be readily analyzed by a variety of methods with little further manipulation. This biofilm preparation method simplifies routine generation of B. subtilis biofilms for molecular and cellular analysis, and could be applicable to other microbial systems.

Screening of Bacillus strains from Luzhou-flavor liquor making for high-yield ethyl hexanoate and low-yield propanol

This study aimed at isolating and culturing Bacilli from the omagari, pit mud, and fermented grains used in Luzhou-flavor liquor in an effort to produce better flavor and quality. After an enrichment culture of Bacillus in the omagari, pit mud, and fermented grains of Luzhou-flavor liquor, 52 total strains were obtained. Based on the standard of producing high-yield ethyl hexanoate and low-yield propanol, one strain named YB-1 was screened out. It was shown that YB-1 produced ethyl hexanoate at 214.7 mg/100 mL and propanol at 0 mg/100 mL. Based on strain morphology, and physiological and biochemical characteristics, YB-1 was identified as Bacillus. According to DNA sequencing and the constructed phylogenetic tree, YB-1 and Bacillus cereus strain CCM 2010 clustered into a branch and were each other's closest relatives. Thus, YB-1 was identified as Bacillus cereus. Through this research, it is expected that the application of Bacillus cereus strain YB-1 to the traditional brewing process of Luzhou-flavor liquor could improve the flavor and quality, and enrich microbial resources for Luzhou-flavor liquor fermentation.

High-performance thin-layer chromatography (HPTLC) for the simultaneous quantification of the cyclic lipopeptides Surfactin, Iturin A and Fengycin in culture samples of Bacillus species.

A high-performance thin-layer chromatography method has been established for the identification and simultaneous quantification of the cyclic lipopeptides Surfactin, Iturin A and Fengycin in Bacillus culture samples. B. subtilis DSM 10T, B. amyloliquefaciens DSM 7T and B. methylotrophicus DSM 23117 were used as model strains. Culture samples indicated that a sample pretreatment is necessary in order to run HPTLC analyses. A threefold extraction of the cell-free broth with the solvent chloroform/methanol (2:1, v/v) gave best results, when all three lipopeptides were included in the analysis. For the mobile phase, a two-step development was considered most suitable. The first development is conducted with chloroform/methanol/water (65:25:4, v/v/v) over a migration distance of 60mm and the second development using butanol/ethanol/0.1% acetic acid (1:4:1, v/v/v) over a migration distance of 60mm, as well. The method was validated according to Validation of Analytical Procedures: Methodology (FDA Guidance) with respect to the parameters linearity, limit of detection (LOD), limit of quantification (LOQ), precision, accuracy and recovery rate. A linear range with R2>0.99 was obtained for all samples from 30ng/zone up to 600ng/zone. The results indicated that quantification of Surfactin has to be performed after the first development (hRF=44), while Fengycin is quantified after the second development (hRF=36, hRF range=20-40). For Iturin A, the results demonstrated that quantification is in favor after the first (hRF=19) development, but also possible after the second (hRF=59) development. LOD and LOQ for Surfactin and Iturin A after the first development, and Fengycin after the second development were determined to be 16ng/zone and 47ng/zone, 13ng/zone and 39ng/zone, and 27ng/zone and 82ng/zone, respectively. Results further revealed the highly accurate and precise character of the developed method with a good inter- and intraday reproducibility. For the precision and accuracy, expressed as % recovery and relative standard deviation, respectively, the determined values did not exceed ±15% as specified by the FDA Guidance. The recovery assay conducted for samples obtained from two strains with the solvent chloroform/methanol (2:1, v/v), which was determined to be most suitable if all three lipopeptides are of interest, gave recoveries of 96.5% and 99.6%, 68.6% and 71.6%, and 102.5% and 95.2% for Surfactin, Iturin A and Fengycin, respectively. Overall, a suitable and reliable method for the simultaneous quantification of the lipopeptides Surfactin, Iturin A and Fengycin in biological samples using HPTLC was successfully developed and validated.

Short-term Supplementation with a Trace Mineral-fortified Microbial Culture May Increase Trace Minerals in Longissimus dorsi Muscle and Prevent Incidence of Urolithiasis in Finishing Hanwoo Steers

This study evaluated the effects of TMC (trace mineral-fortified microbial culture) supplementation on growth performance, carcass characteristics, and meat quality parameters of Hanwoo steers during the last 4 months of finishing period. The TMC was a combination of 0.4% trace minerals, 20.0% Na-bentonite, and 79.6% feedstuffs, which was inoculated with a mixed microbial culture (Enterobacter ludwigii, Bacillus cereus, B. subtilis, Lactobacillus plantarum, and Saccharomyces cerevisiae). Twenty-four steers were blocked by initial BW (634 ± 16 kg) and randomly allocated to one of two treatments (control vs. 3.3% TMC). The effect of TMC supplementation on the growth performance was not significant. There was no incidence of urolithiasis in TMCfed steers. However 3 out 12 steers (25%) fed the control diet were observed to have urinary calculi. The carcass yield and meat quality parameters were not affected by TMC supplementation, however marbling score was increased in TMC-fed steers (P = 0.08). There was no effect of TMC treatment on the chemical composition of longissimus dorsi muscle (LM). The TMC supplementation increased concentrations of manganese (P < 0.01), cobalt (P = 0.02), iron, and copper (P = 0.06) in LM. In conclusion, TMC treatment did not negatively affect growth performance and meat quality parameters, and positively affected the trace minerals profile of LM.

Effect of probiotics on digestive enzyme activities and growth of cichlids,Etroplus suratensis(Pearl spot) andOreochromis mossambicus(Tilapia)

In aquaculture, exposure to stressful conditions and problems related to diseases often occur resulting in serious economic loss. The use of probiotics that control pathogens through different mechanisms, aiding digestion by exoenzyme supply and establishment of beneficial microflora in the digestive tract has got increased attention recently. Two different bacterial species Micrococcus MCCB 104 and Bacillus MCCB 101 were tested as probiotics for two cichlid species Etroplus suratensis and Oreochromis mossambicus. The strains were administered separately and together, at a rate of 103 CFU animal−1 day−1 for 28 days. The effects on digestive enzyme activity and growth were compared with those fed on control diet. FCR of E. suratensis was high in case of Bacillus alone as well as the mixed culture (Micrococcus and Bacillus together) than that of control. However, the SGR of E. suratensis was slightly lower than that of control during 14 days trial. SGR of both the treatments (Bacillus alone and mixed culture) was higher than that of the control on 28th day, and this might be due to the reason that specific duration is needed for the assimilation and conversion of nutrients into proteins. The intestinal digestive hydrolases of E. suratensis were profoundly enhanced mainly by Bacillus and mixed cultures. The hepatopancreatic versions of major digestive enzymes in E. suratensis were influenced variously by different probiotic treatments. The alpha-amylase activity of hepatopancreas has been elevated significantly by mixed culture during 14 days experiments while on 28 days trials both Bacillus and mixed culture showed an enhancing effect. During 14 days feeding trials, the intestinal lipase activity has been prominently enhanced by all probiotic treatments. It is found that, in O. mossambicus, both 14 days and 28 days feeding experiments, the pepsin as well as intestinal digestive enzymes such as amylase, total alkaline protease, lipase and their hepatopancreatic counter parts showed a significant elevation in their specific activity. Intestinal alpha-amylase and total alkaline proteases of O. mossambicus showed an increase in specific activities on both 14 days and 28 days feeding experiments with the Bacillus and Micrococcus combination. The hepatopancreatic enzymes were highly influenced by the Bacillus species in O. mossambicus. The results of this study suggest that live probiotic microorganisms such as Micrococcus MCCB 104 and Bacillus MCCB 101 may be incorporated while formulating the cost-effective, nutritionally balanced diet of E. suratensis and O. mossambicus for better growth performance and nutrient utilization.

Metal Leaching and Reductive Dissolution of Iron from Contaminated Soil and Sediment Samples by Indigenous Bacteria and Bacillus Isolates

ABSTRACTThe purpose of this study was to leach Cu, Zn, As, and Fe from contaminated soil and sediment samples with indigenous heterotrophic bacteria isolated from the study sites. The sediment contained Fe in the form of goethite and low concentrations of other metals. The soil contained hematite and high concentrations of other metals. The environmental conditions affected the bacterial activity in the metals dissolution. As and Fe were the major metals leached from the sediment sample while a minor fraction of Cu was solubilized. Cu and Zn were the major metals leached from the soil sample while only a minor fraction of Fe was dissolved. As a control, a disinfectant was used for partial inactivation of indigenous bacteria. This treatment had a negative effect on the leaching of Fe, Zn and As from soil and sediment samples, but it increased Cu dissolution from the sediment. Bacterial different dissolution of Fe during soil and sediment bioleaching was also investigated with ferrihydrite. The iron concentration was much higher during ferrihydrite dissolution when indigenous bacteria from sediment were used compared to indigenous bacteria isolated from soil. The indigenous bacterial inoculum provided more biological and metabolic diversity which may account for the difference in reductive iron reduction from ferrihydrite. The Bacillus cultures isolated from soil and sediment samples showed similar efficiencies in reductive dissolution of ferrihydrite. The synergetic bacterial inhibition effect created by the environmental conditions can influence bioremediation effect.

Simultaneous removal of Cr(VI) and phenol from synthetic binary solution using consortium culture of Bacillus sp. and E. coli immobilized on tea waste biomass in packed bed reactor

A continuous bio column reactor was designed for the simultaneous bioaccumulation of Cr(VI) and biodegradation of phenol from their binary synthetic solution with the ratio of (2: 1). Consortium culture of Bacillus sp. and Escherichia coli was immobilized onto tea waste biomass in the packed bed column. The metabolites formed during the biodegradation of phenol by Bacillus sp. were utilized by Escherichia coli for the bioaccumulation of Cr(VI). The considerable effect of empty bed contact time (EBCT), bed height (cm) and flow rate (mL/min) was investigated onto the simultaneous removal of Cr(VI) and phenol in the column reactor. However, after 3-4 days of continuous treatment of Cr(VI) and phenol the effect of these process parameters was not significant. Dissolved oxygen (DO) of effluent has been found to decrease with run time of packed bed column. The pH of the effluent decreased initially for 2 days but after that it became the same as the influent. A mass transfer study was carried out to calculate the pseudofirst-order rate constant for Cr(VI) and phenol, which was in good agreement with experimental results.

CodY Regulates SigD Levels and Activity by Binding to Three Sites in the fla/che Operon.

Exponentially growing cultures of Bacillus subtilis (PY79) are composed primarily of nonmotile, chained cells. The alternative sigma factor, SigD, promotes the phenotypic switch from nonmotile, chained cells to unchained, motile cells. In the present work, we investigated the role of the GTP-sensing protein CodY in the regulation of SigD. Deletion of codY resulted in a significant increase in SigD accumulation and activity and shifted the proportion of unchained cells up from ∼15% to ∼75%, suggesting that CodY is an important regulator of SigD. CodY was previously shown to bind to the PD3 and Pfla/che promoters located upstream of the first gene in the sigD-containing fla/che operon. Using electrophoretic mobility shift assays, we found that CodY also binds to two other previously uncharacterized sites within the fla/che operon. Mutations in any one of the three binding sites resulted in SigD levels similar to those seen with the ΔcodY mutant, suggesting that each site is sufficient to tip cells toward a maximal level of CodY-dependent SigD accumulation. However, mutations in all three sites were required to phenocopy the ΔcodY mutant's reduced level of cell chaining, consistent with the idea that CodY binding in the fla/che operon is also important for posttranslational control of SigD activity. One way that bacteria adapt quickly and efficiently to changes in environmental quality is to employ global transcriptional regulators capable of responding allosterically to key cellular metabolites. In this study, we found that the conserved GTP-sensing protein CodY directly regulates cell motility and chaining in B. subtilis by controlling expression and activity of SigD. Our results suggest that B. subtilis becomes poised for cell dispersal as intracellular GTP levels are depleted.

Biodegradation of multiple nitrosamines by the Bacillus species LT1C in drinking water biofilters

To better clarify the biodegradation mechanism of nitrosamines at low concentrations and characterize the nitrosamine-reducing strains isolated from biological activated carbon (BAC) filters in drinking water treatment plants. The nitrosamine-reducing bacterial culture Bacillus species LT1C was cultivated, isolated and purified from a pilot filter system using BAC, and was then applied to evaluate the biodegradable capacity for nitrosamines. Five nitrosamines (N-nitrosomethylethylamine, N-nitrosodi-n-propylamine; N-nitrosopyrrolidine and N-nitrosodi-n-butylamine, N-nitrosopiperidine) were biodegraded in mineral salts medium with removal ratios which ranged from 23.6 to 51.2%. The removal ratios achieved by the isolate were in accordance with the structure, LogKow and Henry's constant of the nitrosamines examined. The findings of this study demonstrate increased potential for the establishment of nitrosamine control strategies in the water supply industry.

Processing and Nutritional Composition of Rice Bran

Rice bran is a component of raw rice that is obtained when it is removed from the starchy endosperm in the rice milling process. Processing was carried out by using microwave and probiotic treatment. The study revealed that rice bran was stabilized by microwave heating (2450MHz for 3min). Stabilized rice bran was inoculated with Lactic Acid Bacillus culture and used as probiotic treated rice bran. Free fatty acid percentage of stabilized rice bran ranged from 4.10 to 7.50 from initial to 4th week and in probiotic treated rice bran it was 4.35 to 7.95 up to 4 weeks of storage period. Functional properties of rice bran were analyzed for stabilized and probiotic treated rice bran i.e. bulk density (0.22-0.38g/ml), water absorption (2-3ml/g), oil absorption (1.5-2.5ml/g), water solubility (7.3-8.0%) and swelling power (6.7-7.2%) respectively. Macronutrient composition of stabilized and probiotic treated rice bran for moisture, protein, fat, ash and carbohydrate were 4.30 and 5.40, 17.50 and 19.25, 13.10 and 17.20, 4.92 and 4.64, 52.33 and 48.55 g/100g respectively and it contained 7.85 and 4.96 g crude fibre, 21.17 and 13.10 g insoluble dietary fibre, 2.17 and 1.80g soluble dietary fibre and 23.34 and 14.90g total dietary fibre. Mineral content of stabilized and probiotic treated rice bran for calcium, phosphorous, iron and zinc were 52.10 and 49.90, 1185.20 and 1186.50, 28.10 and 30.05, 6.02 and 5.89 mg/100g respectively. Processing helps in destroying the lipolytic activity using microwave stabilizing technology, which increases the shelf life of rice bran and improves the nutrient content.

Fatty Acid Profiles for Differentiating Growth Medium Formulations Used to Culture Bacillus cereus T-strain Spores.

Microbial biomarkers that indicate aspects of an organism's growth conditions are important targets of forensic research. In this study, we examined fatty acid composition as a signature for the types of complex nutrients in the culturing medium. Bacillus cereus T-strain spores were grown in medium formulations supplemented with one of the following: peptone (meat protein), tryptone (casein protein), soy protein, and brain-heart infusion. Cellular biomass was profiled with fatty acid methyl ester (FAME) analysis. Results showed peptone cultures produced spores enriched in straight-chained lipids. Tryptone cultures produced spores enriched in branched-odd lipids when compared with peptone, soy, and brain-heart formulations. The observed FAME variation was used to construct a set of discriminant functions that could help identify the nutrients in a culturing recipe for an unknown spore sample. Blinded classification tests were most successful for spores grown on media containing peptone and tryptone, showing 88% and 100% correct identification, respectively.

Surfactins in Natto: The Surfactin Production Capacity of the Starter Strains and the Actual Surfactin Contents in the Products

Surfactin-type lipopeptides are suspected of being implicated in the rare food poisonings caused by Bacillus species outside the Bacillus cereus cluster. In order to get information on surfactin levels in actual human foods, bacilli from three commercial samples of a Japanese traditional bean product, natto, were isolated in order to clarify their potential to produce the suspect lipopeptides. The isolated bacilli were characterized as Bacillus subtilis. They were β-hemolytic and gave a positive signal in the PCR screen for genes associated with surfactin production, and their culture extracts were cytotoxic to boar sperm cells. Organic extracts of both Bacillus cultures and the natto samples were analyzed for their surfactin content using ultrahigh-performance liquid chromatography with high-resolution mass spectrometry. All the strains proved to be surfactin producers (15 to 39 μg/ml culture medium); the natto samples contained as much as 2.2 mg g(-1) of surfactins. This means that consumers can ingest at least approximately 80 to 100 mg of surfactins per single 50-g natto serving apparently without suffering any ill effects, indicating a very low human toxicity.

Optimization of Mixed Fermentation Conditions by Mixed Culture of Kefir and Bacillus

Kefir is a kind of fermented milk that is produced by inoculating Kefir grains into milk, mainly consisting of bacteria and yeasts. Bacillus and their metabolites also have found some biotechnological applications in many aspects. The aim of the present study was to evaluate the mixed fermentation conditions by kefir and Bacillus. The results showed that kefir and Bacillus could be mixed fermentation, the suggested optimum fermentation conditions are the following: inoculum size was 4 mL of mixed fermentation agent for per 100 mL medium, the ratio to kefir and Bacillus is 2:1, fermentation temperature of 28 °C and fermentation time of 20 h. Under the optimum fermentation conditions, the viable cell counts of Lactic acid bacteria, yeast and Bacillus could above 1.0×1011, 4.0×1010, and 2.0×109 CFU/mL respectively. After freeze-dried, by adding 10 % ( w/v ) skim milk, 3 % ( w/v ) glycerinum, 3 % trehalose and 1 % ( w/v ) Monosodium glutamate as for cryoprotectant, the viable cell counts could still above 107 CFU/mL after 6 month.

Biodegradation of 2-hydroxyquinoxaline (2-HQ) by Bacillus sp.

An aerobic Gram +ve bacterial strain capable of utilizing 2-Hydroxyquinoxaline (2-HQ) as sole source of carbon and energy was isolated from Chrysanthemum indicum Indian agricultural soil and named as HQ2. On the basis of morphology, physico-biochemical characteristics and 16S rRNA sequence analysis, strain HQ2 was identified as Bacillus sp. The generation time of Bacillus sp. in log phase during growth on 2-HQ is 0.79h or 47.4min. The optimal conditions for 2-HQ degradation by Bacillus sp. were inoculum density of 1.0 OD, pH of 6–8, temperature of 37–45°C and 2-HQ concentration of 500ppm. Among the additional carbon and nitrogen sources, carbon sources did not influence the degradation rate of 2-HQ, but nitrogen sources—yeast extract marginally enhanced the rate of degradation of 2-HQ. GC-MS analysis of the culture Bacillus sp. grown on 2-HQ indicated the formation of dimers from 2 molecules of 2-hydroxyquinoxaline. The formation of dimer for degradation of 2-HQ by the culture appears to be the first report to our scientific knowledge.

Bacillus subtilis와 Lactobacillus plantarum에 의한 토마토 첨가 두유 요구르트의 항산화 활성

This study was performed to investigate the effect of types of microorganisms on the antioxidant activity of soybean yogurt by a single or mixed culture of Bacillus subtilis and Lactobacillus plantarum isolated from chunggukjang and kimchi. The fermented soybean milk by Bacillus subtilis exhibited the highest values of total polyphenol, DPPH radical scavenging activity, reducing power and nitrite scavenging activity compared to those of Lactobacillus plantarum or mixed culture of Bacillus subtilis/Lactobacillus plantarum. As the amount of tomato extract was added to the soybean milk, various antioxidant parameters, such as total polyphenol, DPPH radical scavenging activity, reducing power and nitrite scavenging activity, were linearly increased.

HIDROLISIS GUGUS METOKSIL PEKTIN AMPAS TEBU UNTUK MENGHASILKAN BIOMETANOL

&lt;p&gt;Methanol is a potential in two areas, namely as fuel cells and biodiesel. Among the many biomass, pectin is one of the best for the production of methanol. The purpose of this study was to determine the influence of pectin methyl esterase enzyme concentration (PME) group metoksil rough on pectin hydrolysis of bagasse to produce the highest levels of biometanol.&lt;/p&gt; &lt;p&gt;Methods This study includes the preparation of the bagasse, further hydrolysis using crude extract of the enzyme pectin methyl esterase (PMEs) resulting from bacterial culture Bacillus subtilis at Borth Nutrient media (NB) with 1% pectin. Hydrolysis of Metoksil groups of poligalakturonat acid in the pectin bagasse to obtain the concentration of methanol to vary the enzyme crude extract PMEs. Concentration of crude enzyme extract PMEs used was 10%, 15%, 20% and 25% in 24-hour incubation with 2 repetitions performed. The resulting methanol levels were analyzed using GC (Gas Chromatography).&lt;/p&gt; The results of this study concluded that allowing the concentration used for hydrolysis of bagasse to produce methanol using crude enzyme from Bacillus subtilis (PMEs) is 10% with a methanol content of 0.02%.