Brevibacillus Agri Research Articles

Isolation and Identification of Pathogenic Bacteria in Pasteurized Powdered Milk Sold in Ogun, Lagos and Oyo, Southwest, Nigeria

Study’s Novelty/Excerpt This study provides novel insights into the bacteriological quality of powdered milk sold in Ogun, Lagos, and Oyo, Southwest Nigeria, by isolating and identifying bacterial species through 16S rRNA gene sequencing and evaluating their antibiotic resistance profiles. The research highlights the detection of potentially harmful bacteria, including Pseudomonas aeruginosa and Bacillus cereus, indicating issues related to inadequate storage or sanitation practices in the milk supply chain. These findings underscore the importance of rigorous microbial monitoring and improved hygiene standards to ensure the safety and extended shelf life of powdered milk products. Full Abstract Milk is a nutritious beverage enjoyed by people of all ages, but it also provides an ideal environment for the growth of various microorganisms. This study aimed to isolate and identify the bacteriological quality of powdered milk sold in Ogun, Lagos, and Oyo, Southwest Nigeria. Three samples from each of five different brands were analyzed by homogenizing 1g of each milk sample with 10ml of nutritional broth, followed by overnight incubation at 37°C. Subsequently, the bacteria were plated on nutrient agar, Mac-Conkey, and EMB, with further characterization through partial sequencing of 16S rRNA genes. The detected species were then evaluated against antibiotics including Acyclovir, Cefotaxime, Augmentin, Cefuroxime, Gentamicin, Erythromycin, Ofloxacin, Nitrofurantoin, Ciprofloxacin, Nalidixic acid, and Azithromycin. The molecular testing revealed the presence of Pseudomonas aeruginosa, Bacillus cereus, Brevibacillus agri, Lysinibacillus sphaericus, and Bacillus thuringiensis as the identified bacterial species. Pseudomonas aeruginosa exhibited sensitivity to Gentamicin and Cefuroxime, with Nitrofurantoin showing the highest sensitivity at 80.0%. Brevibacillus agri (LATC3) demonstrated sensitivity to Cefuroxime and Gentamicin, with a higher sensitivity of 55.00% to Gentamicin. Bacillus cereus (LAKG2 and LAC2) showed higher responsiveness to Ceftriaxone compared to Ofloxacin, Cefotaxime, Augmentin, Acyclovir, and Levofloxacin. These findings indicate the presence of potentially harmful organisms in the microbial populations of pasteurized milk, suggesting inadequate storage practices or insufficient sanitation of facilities and equipment post-production and packaging. Therefore, monitoring the microbial quality of pasteurized milk is essential to ensure safety and extend its shelf life.

Effect of Plant Growth-Promoting Bacteria (PGPB) on the Development of Pea crop (Pisum sativum L.)

Microorganisms are of great importance in agriculture in terms of plant nutrients by reducing the need for chemical fertilization. In recent years, plant growth-promoting bacteria (PGPB) have been widely used as biological fertilizers (BF) in agriculture. This study was conducted to determine the effect of plant growth-promoting bacteria on the development of pea plants. Firstly the phosphate solubilization and nitrogen fixation potentials of the bacteria used in this study were determined. In the study, the effects of 4 different combinations, F1 [(Rhizobium sp. (FR-13) and Pseudomonas alcaligenes (FDG121)], F2 [(Pseudomonas fluorescens biotype F (FDG-7), Rhizobium sp. (FR-18) and Bacillus-megaterium-GC subgroup B(FDG-134)], F3 [Arthrobacter oxydans (FDG-72), Bacillus-megaterium-GC subgroup B (FDG-146), Rhizobium sp. (FR-11)] and F4 [Acinetobacter genospecies 9 (FDG-116), Brevibacillus agri (FDG-118), Methylobacterium zatmanii (FDG-123) and Bacillus-megaterium-GC subgroup A (FDG-153)] were investigated. Formulations made with bacteria that were found to be the best in terms of the properties specified among these strains were tested against pea plants under greenhouse conditions and their effects on the plant's total fresh and dry weight were investigated. The study was set up to have 3 replications. As a result of the statistical analysis made with the data obtained, the formulations used compared to the control; F2, F3 and F1 applications were important in total fresh weight, respectively, and F2 and F3 applications were important in total dry weight. As a result, these 3 formulations are especially effective on the yield of pea plants and can be used as potential biofertilizers.

Draft genome sequences of representative Paenibacillus polymyxa, Bacillus cereus, Fictibacillus sp., and Brevibacillus agri strains isolated from Amazonian dark earth.

Here, we report 10 distinct bacterial genomes from Amazonian dark earths, including six identified as Paenibacillus polymyxa, while the remaining four were unique representatives of Paenibacillus vini, Bacillus cereus, Brevibacillus agri, and Fictibacillus sp., respectively. Each strain exhibited antagonistic activity against Fusarium oxysporum, underscoring their potential as sustainable agriculture resources.

Thermostable Bacterial Laccase: Catalytic Properties and Its Application in Biotransformation of Emerging Pollutants.

Laccases have been predominantly reported in fungi, and primarily, fungal laccases are currently exploited in industrial applications. However, extremophilic bacterial laccases possess immense potential, as they can withstand extreme temperatures, pH, and salt concentrations. In addition, unlike fungal laccases, the production of bacterial laccases is cost-effective. Therefore, bacterial laccases are gaining significant attention for their large-scale applications. Previously, we reported a novel thermostable laccase (LacT) from Brevibacillus agri. Herein, we have confirmed that LacT shares a high sequence similarity with CotA laccase from Bacillus amyloliquefaciens. Peptide mass fingerprinting of LacT was conducted via matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF/MS-MS). Inductively coupled plasma-optical emission spectroscopic (ICP-OES) analysis revealed the presence of ∼3.95 copper ions per protein molecule. Moreover, the secondary and tertiary structure of LacT was studied using circular dichroism (CD) and fluorescence spectroscopy. The absence of notable shifts in CD and fluorescence spectra with an increase in temperature established that LacT remains intact even at elevated temperatures. Analysis of the thermal denaturation profile of LacT by thermogravimetric analysis (TGA) also confirmed its temperature stability. Thereafter, we exploited LacT in its application for the bioremediation of phenolic endocrine disruptors, namely, triclosan, 4,4'-dihydroxybiphenyl, and dienestrol. LacT oxidizes 4,4'-dihydroxybiphenyl and triclosan but no LacT activity was detected with dienestrol. The rate of biotransformation of 4,4'-dihydroxybiphenyl and triclosan increased in the presence of CuSO4 and a redox mediator, ABTS. Transformation of dienestrol was observed only with LacT in the presence of ABTS. This study establishes the application of LacT for the bioremediation of phenolic compounds.

Formulation of Brevibacillus agri and compost to improve growth and phytochemicals compound of Piper caninum herbal plant

Most herbal plant farming operations still rely on conventional methods, negatively impacting human health and the environment. However, by using rhizobacteria to boost the yield and quality of herbal plants, farmers can make a more environmentally responsible and safe choice for consumers. Therefore, the present study aimed to determine the dosage of Brevibacillus agri added to the medicinal plant Piper caninum to boost its growth and phytochemical content. Piper caninum is a popularly used medicinal plant with antifungal and antibacterial properties and the ability to improve the quality of mouse sperm. The investigation was carried out in a greenhouse using a randomized group approach. The results indicated that the most effective formula for promoting growth and enhancing phytochemical composition was F1 (100 g of compost and 3 kg of soil plus 1% Brevibacillus agri), which contained 1% B. agri. Treating the Piper caninum plant with 1%, 2%, or 3% B. agri yielded positive results, likely due to the bacteria's nitrogen-fixing ability and favorable outcomes for the IAA test and protease enzyme. Brevibacillus agri was also found to colonize the roots of Piper caninum and produce the phytochemicals butanoic acid, propanediol, and cyclopropane. In conclusion, using rhizobacteria in sustainable agriculture was highly effective, providing an ecologically responsible and safe alternative to conventional farming methods.

Effects of bacterial composition and aquatic habitat metabolites on malaria vector larval availability in irrigated and non-irrigated sites of Homa Bay county, western Kenya.

Gravid Anopheles malaria vectors depend on both chemical and physical (including microbial) cues for selection of preferred habitats for oviposition. This study focused on assessing the effects of bacterial composition and habitat metabolites on malaria vector larval availability in irrigated and non-irrigated potential larval sources. Water samples were collected from larval positive and negative habitats in the irrigated and non- irrigated areas of Homa Bay county. Bacteria cultured from the water samples were subjected to Matrix Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS) for species identification. DNA was extracted from the colonies and polymerase chain reaction (PCR) and sequencing done. Finally, the metabolite composition of larval positive and negative habitats was determined. MALDI-TOF MS results revealed that Bacillus was the only genera identified from larval sources in the non-irrigated zone. In the irrigated area, Shigella was the dominant genera (47%) while Escherichia coli was the abundant species (13/51). Of the sequenced isolates, 65% were Bacillus. Larvicidal isolates Brevibacillus brevis, Bacillus subtilis, and Exiguobacterium profundum were isolated and grouped with Bacillus mojavensis, Bacillus tequilensis, Bacillus stercoris, and Brevibacillus agri. Irrigated areas with larvae had reduced crude fat (0.01%) and protein content (0.13%) in comparison to those without larvae. In irrigated and non- irrigated areas, larval presence was evident in habitats with high total chlorophyll content (1.12 μg/g vs 0.81μg/g and 3.37 μg/g vs 0.82). Aquatic habitats with larvae in both irrigated and non-irrigated areas exhibited higher sugar concentration than habitats without larvae; however, when compared, non-irrigated areas with larvae had higher sugar concentration than similar habitats in irrigated areas. In addition, substantial concentrations of Manganese, Calcium, and Copper were found in aquatic habitats containing larvae in both irrigated and non-irrigated areas. These results allow for prospective examination as potential larvicidal or adulticidal agents and could be considered when designing potential vector control interventions.

Isolation and characterization of quorum quenching bacteria from municipal solid waste and bottom ash co-disposal landfills.

Co-landfilling of bottom ash (BA) accelerates the clogging of leachate collection systems (LCSs) and increases the risk of landfill failure. The clogging was mainly associated with bio-clogging, which may be reduced by quorum quenching (QQ) strategies. This communication reports on a study of how isolated facultative QQ bacterial strains from municipal solid waste (MSW) landfills and BA co-disposal landfills. In MSW landfills, two novel QQ strains (Brevibacillus agri and Lysinibacillus sp. YS11) can degrade the signal molecule hexanoyl-l-homoserine lactone (C6-HSL) and octanoyl-l-homoserine lactone (C8-HSL), respectively. Pseudomonas aeruginosa could degrade C6-HSL and C8-HSL in BA co-disposal landfills. Moreover, P. aeruginosa (0.98) was observed with a higher growth rate (OD600) compared to that of B. agri (0.27) and Lysinibacillus sp. YS11 (0.53). These results indicated that the QQ bacterial strains were associated with leachate characteristics and signal molecules and could be used for controlling bio-clogging in landfills.

Piper caninum extract and Brevibacillus agri mixture suppresses rice leaf spot pathogen; Nigrospora oryzae and improves the production of red rice (Oryza sativa L)

Under the guise of enhancing productivity, using pesticides and artificial fertilizers in agriculture affects both the environment and living things. High chemical residues in food and the environment disrupt the health of consumers. One of the solutions that can bring about a reduction in the use of pesticides and chemicals is switching to organic fertilizers. The application of biopesticides originating from biological sources such as plant extracts and the use of microbes is gaining global acceptance. Therefore, this study aimed to obtain the best biopesticides and biostimulants that could suppress the leaf spot pathogen, Nigrospora oryzae, and increase the growth and yield of Bali red rice. The study contained four treatments, namely untreated control (F0), Piper caninum leaf extract (F1), Brevibacillus agri (F2), and fermented P. caninum leaf extract plus B. agri (F3). The treatments were arranged in a randomized complete block design, and each treatment was replicated three times. The parameters measured were the number of tillers per plant, number of leafs per plant, chlorophyll content, number of grains per panicle, grain weight, and grain yield. Furthermore, antimicrobial and antioxidants were assayed using SEM. GC-MS. At the end of the experiment, the disease index of the leaf spot was measured. The results showed that F3 significantly suppressed leaf spots caused by N. oryzae compared to other treatments, including untreated control in red rice. Additionally, the F3 significantly increased the number of productive tillers, number of grains per panicle, and grain yield compared to all other treatments. The F3 enhanced the crop yield at 6.19 tons/ha, an increase of 50% compared to the untreated control. The SEM.GC-MS results showed the presence of 2.3 butanediol, tetra-decanoic acid, butanoic acid, ethyl ester, benzene propanal, 3-(1,1-dimethylethyl)-a-methyl, a-N-Normethadol in treated plants with P. canicum plus B. agri.

Characterization of heterotrophic nitrification by a thermotolerant Brevibacillus Agri N2 isolated from sewage sludge composting

A thermotolerant strain isolated from sewage sludge (SS) composting was identified as Brevibacillus Agri N2, which showed the efficient capability for heterotrophic nitrification under high-temperature conditions. Incubation at 60 °C, strain N2 could utilize 45.47% of ammonium nitrogen (99.64 mg/L), 68.89% of hydroxylamine nitrogen (51.14 mg/L) and 76.77% of nitrite nitrogen (55.20 mg/L), with a minor part of nitrogen loss for 1.64%, 2.82% and 5.01%, respectively. The successful detection of ammonia monooxygenase, hydroxylamine oxidase, and nitrate oxidoreductase and PCR amplification of amoA, hao and nxrA genes provided evidence of nitrification ability by strain N2. Furthermore, single-factor experiments indicated that the optimal conditions for efficient nitrification performance by strain N2 were succinate as carbon source, 50 °C, C/N 12, pH 8 and 200 r/min. Strain N2 could perform the complete nitrification process, with minimal nitrogen loss at high temperature conditions, which indicated it had the potential for practical application for reducing nitrogen loss of SS composting.

Microbial Treatment of Raw and Primary Treated Sanitary Landfill Leachate by Indigenous Strain Brevibacillus agri.

Landfill leachate is a potential environmental threat. Sanitary landfills are model sites which contains a leachate collection pool and a processing facility to treat it up to environmental standards before discharge. The present study is the very first endeavor to establish leachate treatment efficiency of indigenous microbial strain Brevibacillus agri. Leachate samples were inoculated with isolated strain and incubated for 41days in an orbital shaker. Percent reduction in major water quality parameters was assessed after 0, 7, 21, and 41days of incubation, for understanding the degradation kinetics. Results of the study demonstrate that Brevibacillus agri was effective in improving the wastewater quality of both raw and primary treated leachate. Overall reduction for different water quality parameters was found to be 50% higher for primary treated leachate than that for raw leachate within 21days of incubation. Microbial degradation followed first-order kinetics with rate constants in the range of 0.0047-0.03 and 0.0061-0.074day-1 for raw and primary treated leachate respectively. Calculated half-life of each pollutant parameter was significantly higher in the raw sample (23-147days) as compared to the primary treated one (27-112days). The leachate pollution index (LPI) value of the raw leachate was also found to be > 25% higher than primary treated leachate sample after microbial treatment. Hence, it can be concluded that on site application of primary treatment technology followed by secondary microbial degradation by indigenous microflora, viz., Brevibacillus sp., may prove effective to achieve desirable water quality for safe environmental discharge.

Microbiological contamination profile in soft drinks.

Soft drinks are food matrices propitious to the growth of acidophilic bacteria, yeasts, and filamentous fungi due to their pH, water activity, and the presence of nutrients. Off-flavor, clouding, and package stuffing are the only parameters producers have to detect spoilage when it is often too late for the brand's reputation. In this work, microbiological analyses were performed on non-alcoholic beverages of Brazilian and Bolivian brands. As a result, Gram-positive, Gram-negative, yeast, and filamentous fungi were isolated. Zygosaccharomyces bisporus yeast was isolated from different flavored stuffed products, and Gluconacetobacter liquefaciens and Brevibacillus agri were isolated from packages without visible signs of deterioration. These microorganisms were identified by MALDI-TOF. For products with visible growth of filamentous fungi, microscopic identification keys identified Aspergillus flavus, Penicillium citrinum, Paecilomyces niveus, and Paecilomyces variotii. These work's findings reflect a failure to sanitize raw materials since the isolates' primary origin is the soil and the water, pointing to the lack of process control in soft drinks.

Influence of oxygen on the vinyl acetate elimination pathway and microbial community structure of methanogenic sludge.

Methanogenic-aerobic coupled processes were used to biological degradation of vinyl acetate (VA) to provide evidence of oxygen role for their complete elimination from different angles. First, physiological characterization of a continuous methanogenic-aerobic reactor fed by VA and glucose (G) showed that by adding G, the VA got 100% hydrolyzed to acetate, and then, by adding 1mg·L-1 ·d-1 of dissolved oxygen (DO), this acetate got methanized by 40% and aerobically mineralized by 60%. Second, batch assays in the presence and absence of sodium azide suggest that VA at different concentrations was eliminated by both anaerobic and aerobic metabolic pathways, because without azide and in the presence of 1mg DO·L-1 increased methane and carbon dioxide formation rates at 80% and 75%, respectively. Finally, microbial population dynamics analysis of the reactor by DGGE-sequencing highlighted that Brevibacillus agri (aerobic) and Methanosarcina barkeri (anaerobic) were identified as responsible for VA elimination by up to 98.6%. PRACTITIONER POINTS: Vinyl acetate is removed by simultaneous methanation and aerobic respiration. Methanosarcina barkeri and Brevibacillus agri removed up to 99% of vinyl acetate. DO and VA have a selective effect on the metabolism and population dynamics.

Identification of mercury‐resistant Streptomyces isolated from Cyperus rotundus L. rhizosphere and molecular cloning of mercury (II) reductase gene

Streptomyces is one of mercury‐resistant bacteria which can convert Hg2+ into nontoxic Hg0 . This study aimed to identify mercury‐resistant Streptomyces present in the Cyperus rotundus rhizosphere from artisanal small‐scale gold mining (ASGM) area and clone merA gene to the cloning and expression vectors. Molecular identification was conducted using 16s rRNA gene with the maximum likelihood algorithms. Results revealed that the AS1 and AS2 strains were a group of Streptomyces ardesiacus and the BR28 strain was closed to Brevibacillus agri. The AS2 merA gene was cloned to pMD20 cloning vectors, pGEX‐5x‐1 and pET‐28c expression vectors. The transformation was successfully performed in BL21 and DH5α competent cells. The full length of the merA gene was confirmed to be 1,425 bp. This study is the first research on identifying mercury‐resistant Streptomyces and cloning the full‐length merA gene in Indonesia.

Isolation and identification of some chromium resistant bacteria from some contaminated sites

Heavy metals have fundamentally effect on the biological system and they are straightforwardly harmful to living creatures, particularly human. Expulsion of these pollutants requires advanced and exorbitant technologies. Along these lines, bioremediation with hefty metal-resistant microorganisms could fillin as a less expensive solution. The aims of this study were to select some chromium resistant bacteria in contaminated sites and to determine the inhibitory concentration values for each species. Selection of the chromium resistant isolates was done using nutrient agar plates containing 100mg/l of (K2Cr2O7), and the values of the inhibitory concentrations were determined by agar diffusion method. Strains that resisted the highest concentrations were diagnosed based on the morphological and molecular methods. Molecular diagnosis was performed based on the analysis of the sequence of nitrogenous bases of 16sr RNA gene as well as the genetic tree relationship. Cr(VI) resistant isolates were chosen from a sum of 40 separates and analyzed as follows: Brevibacillus agri, staphylococcus sp., Bacillus sp., Pseudomonas sp., Exigobacterium sp., and Atlantibacter sp. The MIC values were 2500mg/l for Brevibacillus agri and staphylococcus sp. and 1500mg/l for the remaining species. In this paper, various bacteria strains, resistant to high chromium concentration, were isolated and identified, and these native microorganisms can be utilized for bioremediation of chromium.

Molecular and functional analysis of naphthalene-degrading bacteria isolated from the effluents of indigenous tanneries.

During present study, four naphthalene- metabolizing bacteria were isolated from tanneries effluents through enrichment on naphthalene as sole carbon source in minimal salt medium. The bacteria were analyzed to document growth pattern, naphthalene removal efficiency, biochemical and molecular characteristics, antibiotic sensitivity, and metabolic profile. The 16S ribosomal RNA gene sequences were compared through BLAST (basic local alignment search tool) similarity search tool and three isolates were found homologous to Brevibacillus agri strain NBRC 15538 and one similar to Burkholderia lata strain 383. The naphthalene removal efficiencies ranged from 1.16 ± 0.056 mg/h (IUBN1) to 1.379 ± 0.021 mg/h (IUBN26). All isolates were positive for p-nitrophenyl phosphate (PO4 ), esculin, and inulin fermentation tests. Majority were positive for glucosaminidase (IUBN3, 17, and 26) and a few for mannitol and sorbitol fermentation (IUBN1). Identification of metabolites through gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry analysis allowed tracing pathways associated with naphthalene degradation. Intermediates such as cis-dihydrodiolnaphthalene, 2-hydroxychromene-2-carboxylate, 6-hydroxyhexanoic acid, acetyl-CoA confirmed that the present study bacteria can metabolize naphthalene through a pathway which differs from the pathways reported in earlier known bacteria. Due to fast growth rates, high naphthalene removal potentials, and multiple degradation pathways, these bacteria can be exploited for bioremediation of naphthalene.

The isolation and identification of cadmium-resistant Brevibacillus agri C15

Eight Cd-resistant bacteria were isolated from the soil. Based on the resistance and specific growth rate, one isolate from these was chosen. The 16S rRNA (rrs) gene sequence was used to assert this isolate belongs to the genus of Brevibacillus and closely related to Brevibacillus agri (B.agri) DSM 6348T (AB112716). The isolate was termed B.agri C15. The specific growth yields and the Cd-dependent fall in specific growth yield of B.agri C15 was determined under different concentrations of Cd. The current study provides a basis for isolation Cd resistant bacteria with maximum tolerable concentration (MTC) 15 mM Cd from a contaminated soil 490±50 μmolal Cd that could be suitable for a new Cd-bioremediation process; therefore, further studies are needed to investigate this possibility.

Cadmium Removal with Mutant Brevibacillus Agri C15 Cdr Entrapped in Calcium Alginate Gel: a New Process

With large-scale mining and industrial use of cadmium (Cd), contamination with this metal increased steadily, concerns due to its toxicity and potential damage to the environment and human health have led to the introduction of legislation that regulates acceptable environmental concentrations in different contexts. Therefore, many treatment methods for water and soils have been developed to limit the concentration of Cd in the environment and comply with regulations. In this study, a small laboratory bench-scale column reactor was constructed, optimised, and used to evaluate the removal of Cd from artificial groundwater (AGW) with mutant Brevibacillus agri C15 CdR and its wild type B. agri C15 entrapped in calcium alginate beads at different Cd concentrations. The morphological properties of the beads were studied by scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX) spectroscopy and the location of Cd adsorbed in the beads was detected using a dithizone histochemical method. The experimental results showed that the mutant had significantly higher removal rates than its wild type B. agri C15 (9 and 5 nmol per day per gram of biomass, respectively) due to the presence of the Cd-dithizone complexes on the bead containing the mutant, compared with the less presence of these complexes on the beads containing the wild type. In conclusion, a new process was developed that achieved higher Cd removal rate from AGW by the mutant B. agri C15 CdR. In addition, an alternative detection method of Cd (Cd-dithizone complexes) was introduced that showed that Cd was distributed throughout the Cd-loaded beads.

In Vitro Bioaccessibility Assessment as a Tool to Predict the Toxicity of Bioremediation Products

The demand for the development of bioremediation processes designed to maintain healthy environments has increased; however, evaluation of the toxicity of its products is needed. Therefore, the toxicity of the Cd-loaded beads of the bioremediation approach developed in this paper was evaluated by using in vitro human gastrointestinal simulation (BARGE method). Cd-loaded beads were obtained from adsorption experiments of Cd from artificial groundwater (AGW) and natural river water (NRW, Walkham River, England) using Ca-alginate beads containing live cells of the mutant Brevibacillus agri C15 CdR and its wild type B. agri C15, in batch flasks. The results showed that the Ca-alginate beads containing the mutant adsorped a significant concentration of Cd (1700 mmolal), related to its adsorption capacity. Cd-loaded beads had higher concentrations of Ca and Na (2030 ± 40 and 4300 ± 18 molal, respectively), related to its composition. The effects of the gastrointestinal simulation showed that Ca had the highest bioaccessible concentrations from Cd-loaded beads of all tested elements (Al, Ca Co, Cu, Fe, K Mg, Na, and Zn) from (1280 ± 13.00 molal); while some other elements were not detected at the end of the gastrointestinal system. Cd bioaccessibility was significantly lower in the Cd-loaded beads containing the mutant (0.17 and 0.14 molal in the gastric and gastrointestinal phases, respectively), compared to the wild type (0.23 and 0.19 molal, respectively). The bioaccessible fractions (BAFs) of Cd were significantly lower in the Cd-loaded beads containing the mutant at the gastric and gastrointestinal phase, with the mean of 4.85 % and 2.95 %, respectively. The low percentages of BAFs of Cd suggested that the products of the bioremediation process developed in this project might not be relevant as a human health risk.

Characterization of Multi-Potential Toluene Metabolizing Bacteria Isolated from Tannery Effluents

The focus of present study was to isolate and characterize toluene metabolizing bacteria and evaluate their bioremediation potential. During present study bacteria were isolated from the tannery effluents using selective enrichment and serial dilution methods. The growth behavior, toluene removal efficiencies, biochemical and molecular characteristics and antibiotic resistance profiles of isolated bacteria were documented through standard procedures. Toluene degradation was also confirmed using GC-MS and LC-MS analysis of metabolites. Present study isolates (n = 20) showed top BLAST sequence similarity with Brevibacillus agri strain NBRC 15538 (75%), Bacillus paralicheniformis strain KJ-16 (20%) and Burkholderia lata strain 383 (5%). The rRNA gene sequences have been submitted to GeneBank. All present study isolates exhibited remarkable toluene removal potential and most of these were slow-growing. Biochemical characterization indicated bacteria positive for alkaline phosphatases (100%), D-glucosaminidase (35%), naphthylaminopeptidase (15%), esculinase (65%), mannitol (75%), sorbitol (95%) and inulin (90%) fermentation. Biochemical profile suggests the use of isolated bacteria for future exploitation in several fields like toluene bioremediation, ethanol production, biomass hydrolysis, biosensors, biofertilizers, as a marker for milk pasteurization in dairy industries.

Isolation and Identification of Resistant Microorganisms from Automotive Paint Sludge

Background: Paint coating systems are widely implemented on different surfaces for both aspects of decoration and protection against corrosion. Due to the presence of organic compounds, the growth of microorganisms is more likely to take place in paints, such as automotive paint. In the process of automotive painting, 20% - 60% of the paint does not expose to the automotive body, which is washed using water and would lead to the painting sludge formation. Paint sludge is considered one of the hazardous wastes from the automotive industry, which is finally landfilled or incinerated. Objectives: Despite the presence of inhibiting compounds in paint sludge, such as heavy metals and biocides, the objective of this study was to isolate and identify microorganisms in the sludge culture. Methods: The microorganisms were isolated using serial dilutions, direct cultivation, and enrichment methods in basic salt cultivation media. Then, their biochemical and molecular specifications were investigated. Results: The number of microorganisms counted in paint sludge was approximately around 1 × 104 CFU/mL, and six isolated colonies were finally obtained. Conclusions: The main isolated microbial consortium from paint sludge included Pseudomonas aeruginosa, Staphylococcus haemolyticus, Micrococcus yunnanensis, Rothia amarae, Gordonia terrae, and Brevibacillus agri. Nearly 83% of the isolated strains were Gram-positive.