Mitigation of Hyper KCl Stress at 42ºC with Externally Existing Sodium Glutamate to a Halotolerant Brevibacterium sp. JCM 6894.

Halotolerant Brevibacterium sp. JCM 6894 grew at 37ºC in the presence of 2.3 M KCl, while the growth was repressed with the same concentration of NaCl. When resting cells, 107.4 ± 0.1 (CFU·mL-1), prepared from cells grown in the absence of salts at 30ºC, were exposed to 3.3 M NaCl for 36 h at 42ºC, reduction of the number of resting cells was maintained within a 1-log cycle in the presence of proline, betaine, or ectoine (50 mM). In the presence of 3.3 M KCl, the most functional osmoprotectant was sodium glutamate (50 mM), and the value was 107.2 ± 0.1 (CFU·mL-1) when exposed for 72 h at 42ºC. In the absence of osmoprotectants, the value was reduced to four orders of magnitude in each experimental condition. The number of resting cells, 106.8 ± 0.1 (CFU·mL-1), prepared from grown cells pre-adapted to 2.3 M KCl at 37ºC, was hardly reduced when exposed to 3.3 M KCl in the presence of sodium glutamate more than 50 mM for 72 h at 42ºC. Those results indicate that the isolate can sense the difference in hyper KCl stress as opposed to hyper NaCl stress, and different kinds of osmoadaptation systems can function to cope with each hyper salt stress.

Alkaline Protease Production from Brevibacterium luteolum (MTCC 5982) Under Solid-State Fermentation and Its Application for Sulfide-Free Unhairing of Cowhides.

Enzyme-based unhairing in replacement of conventional lime sulfide system has been attempted as an alternative for tackling pollution. The exorbitant cost of enzyme and the need for stringent process control need to be addressed yet. This study developed a mechanism for regulated release of protease from cheaper agro-wastes, which overcomes the necessity for stringent process control along with total cost reduction. The maximum protease activity of 1193.77 U/g was obtained after 96 h of incubation with 15% inoculum of the actinomycete strain Brevibacterium luteolum (MTCC 5982) under solid-state fermentation (SSF). The medium after SSF was used for unhairing without the downstream processing to avoid the cost involved in enzyme extraction. This also helped in the regulated release of enzyme from bran to the process liquor for controlled unhairing and avoided the problem of grain-pitting. Unhairing process parameters were standardized as 20% enzyme offer, 40% Hide-Float ratio at 5 ± 1 rpm, and process pH of 9.0. The cost of production of 1000 kU of the protease was calculated as 0.44 USD. The techno-economic feasibility studies for setting up an SSF enzyme production plant showed a high return on investment of 15.58% with a payback period of 6.4 years.

Reclassification of Brevibacterium halotolerans DSM8802 as Bacillus halotolerans comb. nov. Based on Microbial and Biochemical Characterization and Multiple Gene Sequence.

Brevibacterium halotolerans is currently classified as a member of the Brevibacterium genus, a genus that groups together many bacterial species of similar morphology but diverse biochemical and physiological features. Here we suggest, based on multiple gene sequencing and microbial and biochemical characterization of two environmental isolates and one type strain (DSM8802), that the B. halotolerans DSM8802 (and probably the other deposited under this species name) should be re-classified into the Bacillus genus, and offered the name B. halotolerans comb. nov.

Eco-friendly approach towards green synthesis of zinc oxide nanocrystals and its potential applications.

In the present study, we investigated a novel green route for synthesis of zinc oxide (ZnO) nanocrystals using Prunus × yedoensis Matsumura leaf extract as a reducing agent without using any surfactant or external energy. Standard characterization studies were carried out to confirm the obtained product using UV-Vis spectra, SEM-EDS, FTIR, TEM, and XRD. In addition, the synthesized ZnO nanocrystals were coated onto fabric and leather samples to study their bacteriostatic effect against odor-causing bacteria Brevibacterium linens and Staphylococcus epidermidis. Zinc oxide nanocrystal-coated fabric and leather showed good activity against both bacteria.

Brevibacterium frigoritolerans as a Novel Organism for the Bioremediation of Phorate.

Phorate, an organophosphorus insecticide, has been found effective for the control of various insect pests. However, it is an extremely hazardous insecticide and causes a potential threat to ecosystem. Bioremediation is a promising approach to degrade the pesticide from the soil. The screening of soil from sugarcane fields resulted in identification of Brevibacterium frigoritolerans, a microorganism with potential for phorate bioremediation was determined. B. frigoritolerans strain Imbl 2.1 resulted in the active metabolization of phorate by between 89.81% and 92.32% from soils amended with phorate at different levels (100, 200, 300 mg kg(-1) soil). But in case of control soil, 33.76%-40.92% degradation were observed. Among metabolites, sulfone was found as the main metabolite followed by sulfoxide. Total phorate residues were not found to follow the first order kinetics. This demonstrated that B. frigoritolerans has potential for bioremediation of phorate both in liquid cultures and agricultural soils.

Antioxidant/Prooxidant and antibacterial/probacterial effects of a grape seed extract in complex with lipoxygenase.

In an attempt to determine the antioxidant/prooxidant, antibacterial/probacterial action of flavan-3-ols and procyanidins from grape seeds, pure catechin (CS), and an aqueous grape seed extract (PE), were applied in the absence and presence of pure lipoxygenase (LS) or in extract (LE) to leucocyte culture, Escherichia coli B 41 and Brevibacterium linens, and observed whether there was any effect on lipid peroxidation, cytotoxicity, or growth rate. Short time periods of coincubation of cells with the polyphenols, followed by the exposure to LS and LE, revealed a high level of lipid peroxidation and a prooxidative effect. Longer coincubation and addition of LS and LE resulted in the reversal of the prooxidant action either to antioxidant activity for CS + LS and PE + LS or to the control level for CS + LE and PE + LE. Lipid peroxidation was significantly reduced when cells were exposed to polyphenols over a longer period. Longer exposure of E. coli to CS or PE followed by addition of LS for 3 h resulted in bactericidal activity. Significant stimulatory effect on microbial growth was observed for PE + LS and PE + LE treatments in B. linens, illustrating the potential probacterial activity in B. linens cultures. Lipoxygenase-polyphenols complex formation was found to be responsible for the observed effects.

Growth enhancement of the halotolerant Brevibacterium sp. JCM 6894 by methionine externally added to a chemically defined medium.

We examined amino acid requirements for the growth of the halotolerant Brevibacterium sp. JCM 6894 in the absence and presence of 1.2 M NaCl in a chemically defined medium. The experiment was also carried out in the presence of 1.2 M KCl. As a result, growth was highly enhanced by methionine in the absence and presence of KCl as well as NaCl up to 1.2 M. However, growth in the presence of 150 mM methionine was repressed by leucine (up to 100 mM）and valine (up to 100 mM). Concentration-dependent growth inhibition was observed in the presence of isoleucine (up to 150 mM) and threonine (up to 300 mM). When the cells were incubated in the absence of externally added K+, growth was strongly repressed, even in the presence of 150 mM methionine. The growth, however, recovered drastically by the addition of 1 mM KCl, regardless of the presence and absence of 1.2 M NaCl. These results indicate that methionine, which seems to be symported into cytoplasm with K+, plays an important role in the growth of the strain under salt stress.

[Microbial synthesis of deuterium labelled L-phenylalanine with different levels of isotopic enrichment by facultative methylotrophic bacterium Brevibacterium methylicum with RMP assimilation of carbon].

The preparative microbial synthesis of amino acids labelled with stable isotopes, including deuterium ( 2 H), suitable for biomedical applications by methylotrophic bacteria was studied using L-phenylalanine as example. This amino acid is secreted by Gram-negative aerobic facultative methylotrophic bacteria Brevibacterium methylicum, assimilating methanol via ribulose-5-monophosphate (RMP) cycle of assimilation of carbon, The data on adaptation of L-phenylalanine secreted by methylotrophic bacterium В. methylicum to the maximal concentration of deuterium in the growth medium with 98% 2 Н 2 O and 2% [ 2 Н]methanol, and biosynthesis of deuterium labelled L-phenylalanine With different levels of enrichment are presented. The strain was adapted by means of plating initial cells on firm (2% agarose) minimal growth media with an increasing gradient of 2 Н 2 O concentration from 0; 24.5; 49.0; 73.5 up to 98% 2 Н 2 O followed by subsequent selection of separate colonies stable to the action of 2 Н 2 O. These colonies were capable to produce L-phenylalanine. L-phenylalanine was extracted from growth medium by extraction with isopropanol with the subsequent crystallization in ethanol (output 0.65 g/l). The developed method of microbial synthesis allows to obtain deuterium labelled L-phenylalanine with different levels of isotopic enrichment, depending on concentration of 2 Н 2 O in growth media, from 17% (on growth medium with 24,5% 2 Н 2 O) up to 75% (on growth medium with 98% 2 Н 2 O) of deuterium in the molecule that is confirmed with the data of the electron impact (EI) mass- spectrometry analysis of methyl ethers of N-dimethylamino(naphthalene)-5-sulfochloride (dansyl) phenylalanine in these experimental conditions.

[Bacteria that degrade low-molecular linear epsilon-caprolactam olygomers].

Five bacterial strains with the unique ability to utilize low-molecular linear caprolactam olygomers (nylon olygomers) were isolated from soil samples contaminated with industrial wastes of epsilon-caprolactam. Based on the properties studied and also on the analysis of 16S rRNA gene nucleotide sequences, the strains BS2,BS3, BS9, BS38, and BS57 were classified to the general Arthrobacter, Brevibacterium, Microbacteriun, Gulosibacter, and Achromobacter, respectively. All of the strains also utilized 6-aminohexanoic and adipic acids, which are intermidiates of the epsilon-caprolactam catabolism. This indirectly points to the fact that degradation of olygomers in these bacteria occurs via the monomer degradation pathway. The BS9 and BS57 strains utilized only olygomers of the epsilon-caprolactam, while BS2, BS3, and BS38 also degraded epsilon-caprolactam and its homologs, enantolactam and caprylolactam, which differentiates the latter from the previously known degraders of olygomers and suggests the presence in these strains of enzymes with lactam hydrolase activity, in addition to 6-aminohexanoate-dimer hydrolase.

Isolation and process parameter optimization of Brevibacterium casei for simultaneous bioremediation of hexavalent chromium and pentachlorophenol.

Chromate and pentachlorophenol are major pollutants discharged through tanneries. Three bacteria resistant to high Cr(6+) and PCP concentrations simultaneously were isolated. The TVS-3 strain was tolerant to highest 850 mg l(-1) Cr(6+) and 1000 mg l(-1) PCP concentration and concomitantly reduced 69% Cr(6+) and degraded 72% PCP within 168 h at pH 7.5, 35 ± 1°C temperature, was selected and identified as Brevibacterium casei. At 168 h of growth, bacterium showed maximum PCP utilization of 720 mg l(-1) and released 900 mg l(-1) chloride ion. The bacterium exhibited remarkable ability to significantly reduce Cr(6+) and degrade PCP in presence of other metals, between 100-120 rpm aeration and over broad pH (6.5-10.0) and temperature (30-40°C) range. Maximum 78% Cr(6+) reduction and 82% PCP degradation was observed at pH 8.0, 35 ± 1°C within 168 h of incubation, 120 rpm and initial concentration of 850 mg l(-1) Cr(6+) and 1000 mg l(-1) PCP. This is the first study reporting 78% Cr(6+) reduction and 82% PCP degradation simultaneously by single native bacteria under wide growth conditions utilizing PCP as sole carbon source. This bacterium may potentially be useful for simultaneous bioremediation of Cr(6+) and PCP containing wastes in the environment.

Temperature and relative humidity influence the microbial and physicochemical characteristics of Camembert-type cheese ripening.

To evaluate the effects of temperature and relative humidity (RH) on microbial and biochemical ripening kinetics, Camembert-type cheeses were prepared from pasteurized milk seeded with Kluyveromyces marxianus, Geotrichum candidum, Penicillium camemberti, and Brevibacterium aurantiacum. Microorganism growth and biochemical changes were studied under different ripening temperatures (8, 12, and 16°C) and RH (88, 92, and 98%). The central point runs (12°C, 92% RH) were both reproducible and repeatable, and for each microbial and biochemical parameter, 2 kinetic descriptors were defined. Temperature had significant effects on the growth of both K. marxianus and G. candidum, whereas RH did not affect it. Regardless of the temperature, at 98% RH the specific growth rate of P. camemberti spores was significantly higher [between 2 (8°C) and 106 times (16°C) higher]. However, at 16°C, the appearance of the rind was no longer suitable because mycelia were damaged. Brevibacterium aurantiacum growth depended on both temperature and RH. At 8°C under 88% RH, its growth was restricted (1.3 × 10(7) cfu/g), whereas at 16°C and 98% RH, its growth was favored, reaching 7.9 × 10(9) cfu/g, but the rind had a dark brown color after d 20. Temperature had a significant effect on carbon substrate consumption rates in the core as well as in the rind. In the rind, when temperature was 16°C rather than 8°C, the lactate consumption rate was approximately 2.9 times higher under 88% RH. Whatever the RH, temperature significantly affected the increase in rind pH (from 4.6 to 7.7 ± 0.2). At 8°C, an increase in rind pH was observed between d 6 and 9, whereas at 16°C, it was between d 2 and 3. Temperature and RH affected the increasing rate of the underrind thickness: at 16°C, half of the cheese thickness appeared ripened on d 14 (wrapping day). However, at 98% RH, the underrind was runny. In conclusion, some descriptors, such as yeast growth and the pH in the rind, depended solely on temperature. However, our findings highlight the fact that the interactions between temperature and RH played a role in P. camemberti sporulation, B. aurantiacum growth, carbon substrate consumption rates, and the thickening of the cheese underrind. Moreover, the best ripening conditions to achieve an optimum between microorganism growth and biochemical kinetics were 13°C and 94% RH.

Biodegradation of bensulfuron-methyl and its effect on bacterial community in paddy soils.

Bensulfuron-methyl (BSM) is a new kind of sulfonylurea herbicide widely used to control broad-leaf weeds in rice paddies. The aim of this work was to study BSM biodegradation in paddy soils with BSM-degrading bacteria Bacillus megaterium L1 and Brevibacterium sp. BH and its effect on the structures of soil bacterial community. More than 90 % of BSM could be degraded in paddy soils with 0.0355 mg kg⁻¹ BSM concentration. Addition of BSM-degrading bacterial strains Bacillus megaterium L1 into BSM contaminated paddy soil could have the half-life time of BSM compared to treatment without Bacillus megaterium L1 inoculation. Denaturing gradient gel electrophoresis and principle component analysis indicated that the diversity of the soil microbial community structure changed along with the addition of BSM, which recovered at the end of the experiment (5 weeks). Addition of BSM-degrading bacteria Bacillus megaterium L1 enriched the diversity of soil microbial community structure in paddy soils. This study provides information on the biodegradation of BSM and BSM's influences on the soil bacteria microbial community structures.

Growth of aerobic ripening bacteria at the cheese surface is limited by the availability of iron.

The microflora on the surface of smear-ripened cheeses is composed of various species of bacteria and yeasts that contribute to the production of the desired organoleptic properties. The objective of the present study was to show that iron availability is a limiting factor in the growth of typical aerobic ripening bacteria in cheese. For that purpose, we investigated the effect of iron or siderophore addition in model cheeses that were coinoculated with a yeast and a ripening bacterium. Both iron and the siderophore desferrioxamine B stimulated the growth of ripening bacteria belonging to the genera Arthrobacter, Corynebacterium, and Brevibacterium. The extent of stimulation was strain dependent, and generally, the effect of desferrioxamine B was greater than that of iron. Measurements of the expression of genes related to the metabolism of iron by Arthrobacter arilaitensis Re117 by real-time reverse transcription-PCR showed that these genes were transcribed during growth in cheese. The addition of desferrioxamine B increased the expression of two genes encoding iron-siderophore ABC transport binding proteins. The addition of iron decreased the expression of siderophore biosynthesis genes and of part of the genes encoding iron-siderophore ABC transport components. It was concluded that iron availability is a limiting factor in the growth of typical cheese surface bacteria. The selection of strains with efficient iron acquisition systems may be useful for the development of defined-strain surface cultures. Furthermore, the importance of iron metabolism in the microbial ecology of cheeses should be investigated since it may result in positive or negative microbial interactions.

Potential of the waste from beer fermentation broth for bio-ethanol production without any additional enzyme, microbial cells and carbohydrates.

The potential of the waste from beer fermentation broth (WBFB) for the production of bio-ethanol using a simultaneous saccharification and fermentation process without any extra additions of saccharification enzymes, microbial cells or carbohydrate was tested. The major microbial cells in WBFB were isolated and identified. The variations in compositions of WBFB with stock time were investigated. There was residual activity of starch hydrolyzing enzymes in WBFB. The effects of reaction modes e.g. static and shaking on bio-ethanol production were studied. After 7 days of cultivation using the supernatant of WBFB at 30 °C the ethanol concentration reached 103.8 g/L in shaking culture and 91.5 g/L in static culture. Agitation experiments conducted at a temperature-profile process in which temperature was increased from 25 to 67 °C shortened the simultaneous process time. The original WBFB was more useful than the supernatant of WBFB in getting the higher concentration of ethanol and reducing the fermentation time. From this whole study it was found that WBFB is a cheap and suitable source for bio-ethanol production.

Biologically synthesized fluorescent CdS NPs encapsulated by PHB.

Here an attempt was made to biologically synthesize fluorescent cadmium sulfide nanoparticles and to immobilize the synthesized nanoparticles in PHB nanoparticles. The present study uses Brevibacterium casei SRKP2 as a potential producer for the green synthesis of CdS nanoparticles. Biologically synthesized nanoparticles were characterized and confirmed using electron microscopy and XRD. The size distribution of the nanoparticles was found to be 10-30 nm followed by which the consequence of time, growth of the organism, pH, concentration of CdCl(2) and Na(2)S on the synthesis of nanoparticles were checked. Enhanced synthesis and fluorescence emission of CdS nanoparticles were achieved at pH 9. The synthesized CdS NPs were immobilized with PHB and were characterized. The fluorescent intensity of the CdS nanoparticles remained unaffected even after immobilization within PHB nanoparticles.

Global regulation of the response to sulfur availability in the cheese-related bacterium Brevibacterium aurantiacum.

In this study, we combined metabolic reconstruction, growth assays, and metabolome and transcriptome analyses to obtain a global view of the sulfur metabolic network and of the response to sulfur availability in Brevibacterium aurantiacum. In agreement with the growth of B. aurantiacum in the presence of sulfate and cystine, the metabolic reconstruction showed the presence of a sulfate assimilation pathway, thiolation pathways that produce cysteine (cysE and cysK) or homocysteine (metX and metY) from sulfide, at least one gene of the transsulfuration pathway (aecD), and genes encoding three MetE-type methionine synthases. We also compared the expression profiles of B. aurantiacum ATCC 9175 during sulfur starvation or in the presence of sulfate. Under sulfur starvation, 690 genes, including 21 genes involved in sulfur metabolism and 29 genes encoding amino acids and peptide transporters, were differentially expressed. We also investigated changes in pools of sulfur-containing metabolites and in expression profiles after growth in the presence of sulfate, cystine, or methionine plus cystine. The expression of genes involved in sulfate assimilation and cysteine synthesis was repressed in the presence of cystine, whereas the expression of metX, metY, metE1, metE2, and BL613, encoding a probable cystathionine-γ-synthase, decreased in the presence of methionine. We identified three ABC transporters: two operons encoding transporters were transcribed more strongly during cysteine limitation, and one was transcribed more strongly during methionine depletion. Finally, the expression of genes encoding a methionine γ-lyase (BL929) and a methionine transporter (metPS) was induced in the presence of methionine in conjunction with a significant increase in volatile sulfur compound production.

[Effect of cultivation parameters of antarctic strains Enterobacter hormaechei and Brevibacterium antarcticumon resistant to copper(II) ions].

Enterobacter hormaechei and Brevibacterium antarcticum strains isolated from ornithogenic soils of Galindez Island (West Antarctica) were investigated for their resistance to Cu2+ cations and for their capacity to Cu2+ uptake from the environment. The studied strains are capable to grow in the concentration range of copper 100-1100 mg/l and to extract 11-75% of Cu2+ from the environment depending on cultivation parameters and copper output concentration in the culture medium.

[Biosynthesis of L-lysine-alpha-oxidase, an antitumor enzyme, by Trichoderma spp].

Strains of Trichoderma spp., producing L-lysine-alpha-oxidase, prospective in chemotherapy of malignant tumors, were studied. The best results of the enzyme biosynthesis were observed on the wheat bran medium. When grown on the media with various pH levels, the strains showed different spectra of the L-aminooxidase activity. The highest activity of the strains was recorded with respect to destruction of L-lysine. The lysine-producing organism Brevibacterium sp. induced L-lysine-alpha-oxidase activity in Trichoderma spp.

Biodegradation of gaseous styrene by Brevibacillus sp. using a novel agitating biotrickling filter.

A novel biofilter with an agitator to control excessive biomass accumulation, the agitating biotrickling filter (ABTF) system, was developed for treatment of gaseous styrene using Brevibacillus sp. as the sole microorganism the ABTF exhibited an elimination capacity of 3 kg styrene m(-3) day(-1). After 110 days, the biodegradation efficiency decreased because of the clogging. The excess biomass was effectively removed by agitation. After the first agitation step, 42.4 g biomass was eliminated, and the removal efficiency increased from 60% to 95%. Stable operation of the ABTF was achieved by controlling the biomass accumulation via the agitation of the filter bed.

Cloth colorization caused by microbial biofilm.

In this study, cloth disfeaturement was investigated biologically. To clarify whether or not microbes can cause cloth disfeaturement, and to identify the microbes causing the disfeaturement, worn cloth samples were incubated on sweat-ingredient agar medium. Non-sterilized cloth samples became yellow-colored during incubation, and bacterial strains belonging to the genera Bacillus, Brevibacterium, Kocuria, Micrococcus and Staphylococcus were isolated from the yellow-colored parts. Two major isolates close to the genera Bacillus and Micrococcus were inoculated separately or together on cloth samples to examine whether or not these isolates can cause colorization. When the isolate close to Micrococcus was inoculated on its own or mixed with the isolate close to Bacillus, the samples turned yellow to a greater extent and a biofilm-like structure was observed by SEM on the colored areas. In contrast, the isolate close to Bacillus alone barely caused any colorization, and no biofilm-like structure was observed. From the yellow-colored samples, bacterial strains with the same 16S rRNA gene sequences as those of the inoculated strains were re-isolated. These results strongly suggest that the bacterial strain belonging to genus Micrococcus causes cloth colorization by forming a biofilm structure.