Isolation and characterization of a polyurethane-degrading bacterium / 生物工程学报

Biodegradation of polyurethane (PUR) pollutants by microorganisms has received widespread attention currently. Identification of microorganisms capable of efficiently degrading PUR plastics is a key point. In this study, a strain P10 capable of degrading PUR was isolated from the plastic wastes, and identified as a bacterium belonging to the genus of Brevibacillus based on colony morphology and 16S rDNA phylogenetic analysis. Brevibacillus sp. P10 was capable of degrading 71.4% of waterborne polyurethane (Impranil DLN) after 6 days growth in MSM medium with DLN as a sole carbon source. In addition, strain P10 can use commercial PUR foam as the sole carbon source for growth. Brevibacillus sp. P10 can degrade 50 mg PUR foam after 6 days growth in MSM medium supplemented with 5% (V/V) LB after optimization of degradation conditions. This indicates that Brevibacillus sp. P10 has potential to be used in biodegradation of PUR waste.

Screening, identification and antagonistic effect evaluation of biocontrol strains to Asarum leaf blight / 中国中药杂志

Leaf blight is the main disease of Asarum. At present, chemical treatment is main measure for disease control, and there is no report on biological control. In order to achieve the biological control of Asarum leaf blight, the biocontrol strains with antagonistic effect on Asarum leaf blight were screened. The rhizosphere bacteria of healthy Asarum plants were isolated by soil dilution method, and the isolated strains were screened by the methods of antagonistic antifungal and fermentation liquid antifungal, then the strains were identified and the control effect in vivo was determined. Abiocontrol bacterial strains S2-31 which with high antagonism to leaf blight was obtained from more than 100 isolated strains. The inhibitory rates of antagonistic antifungal and fermentation liquid antifungal reached 92.47% and 60.56%, respectively. It was identified by morphology and 16 S rDNA sequence analysis, and the strain was identified as Brevibacillus laterosporus. The results of indoor potted experiment showed that the control effect was 79.87%, 71.44% and 66.82% on the 3 rd, 5 th and 7 th day after inoculation, respectively, which indicated that S2-31 could reduce the disease index and control the development of Asarum leaf blight.

Enhanced production and organic solvent stability of a protease fromBrevibacillus laterosporus strain PAP04

A bacterial strain (PAP04) isolated from cattle farm soil was shown to produce an extracellular, solvent-stable protease. Sequence analysis using 16S rRNA showed that this strain was highly homologous (99%) to Brevibacillus laterosporus. Growth conditions that optimize protease production in this strain were determined as maltose (carbon source), skim milk (nitrogen source), pH 7.0, 40°C temperature, and 48 h incubation. Overall, conditions were optimized to yield a 5.91-fold higher production of protease compared to standard conditions. Furthermore, the stability of the enzyme in organic solvents was assessed by incubation for 2 weeks in solutions containing 50% concentration of various organic solvents. The enzyme retained activity in all tested solvents except ethanol; however, the protease activity was stimulated in benzene (74%) followed by acetone (63%) and chloroform (54.8%). In addition, the plate assay and zymography results also confirmed the stability of the PAP04 protease in various organic solvents. The organic solvent stability of this protease at high (50%) concentrations of solvents makes it an alternative catalyst for peptide synthesis in non-aqueous media.

Study on the effect of bacillus licheniformis and live combined bifidobacterium and lactobacillus on chemotherapy- induced diarrhea / 中国医师进修杂志

Objective To study the effect of bacillus licheniformis and live combined bifidobacterium and lactobacillus on chemotherapy-induced diarrhea (CID). Methods Seventy-two gastric cancer patients with CID were collected and the clinical data were analyzed retrospectively. The patients were divided into 4 groups according to different treatment methods with 18 cases each. The patients in group A were treated with montmorillonite powder, the patients in group B were treated with montmorillonite powder and bacillus licheniformis, the patients in group C were treated with montmorillonite powder and live combined bifidobacterium and lactobacillus, and the patients in group D were treated with montmorillonite powder, bacillus licheniformis capsule and live combined bifidobacterium and lactobacillus. The patients with severe diarrhea in 4 groups were treated with rehydration, maintaining water and electrolyte balance and nutritional support. The Karnofsky performance scale score (KPS score), diarrhea grading before and after treatment and treatment effect were recorded. Results The KPS score after treatment in group A, group B, group C and group D were significantly higher than that before treatment: (70.6 ± 10.6) scores vs. (62.2 ± 12.2) scores, (76.1 ± 7.8) scores vs. (61.7 ± 9.9) scores, (77.2 ± 7.5) scores vs. (61.1 ± 10.8) scores, (83.9 ± 5.0) scores vs. (63.9 ± 10.9) scores. Moreover, The KPS score in group B, group C and group D were significantly higher than that in group A, the KPS score in group D was significantly higher than that in group B and group C, and there were statistical differences (P<0.05). The diarrhea grading after treatment in 4 groups were improved compared with that before treatment. Furthermore, the diarrhea grading in group B, group C and group D were significantly better than that in group B and group C, and there were statistical differences (P<0.05). In group A, there were 2 cases with excellent effect, 10 cases with effect and 6 cases with no effect;in group B, there were 8 cases with excellent effect, 8 cases with effect and 2 cases with no effect;in group C, there were 7 cases with excellent effect, 9 cases with effect and 2 cases with no effect; in group D, there were 9 cases with excellent effect, 9 cases with effect and 0 case with no effect. The treatment effect in group D was significantly better than that in the other 3 groups, and there were statistical differences (Hc = 10.81, P<0.05). Conclusions Bacillus licheniformis and live combined bifidobacterium and lactobacillus is more effective in the treatment of gastric cancer patients with CID.

Antimycobacterial activity of a Brevibacillus Laterosporus strain isolated from a moroccan soil

The treatment of tuberculosis has become more difficult with the worldwide spread of multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains of Mycobacterium tuberculosis. Moreover, the prevalence of human disease caused by atypical mycobacteria has also increased in the past two decades and has further complicated the problem of the treatment of mycobacterial infections. It is therefore urgent to develop new highly active molecules against these bacteria. The present study reports the isolation from a Moroccan soil of a Bacillus strain that exhibits an important antimycobacterial activity. The strain was identified as Brevibacillus laterosporus using DNA sequencing of the 16S ribosomal RNA gene. The antimycobacterial activity was assigned to a substance with a protein nature. This nature was revealed using a liquid-liquid extraction with organic solvents, precipitation with ammonium sulfate and treatment with a protease. This study suggested the identification and the characterization of this active metabolite enabling therapeutic investigations further.

Identification and Screening of Broad-spectrum Antibiotics-producing Strains / 微生物学通报

60 strains which have antimicrobial activity had been isolated from nutritious soil in China in the study.We have further selected 1 strain which product broad-spectrum antibiotics using agar well-diffusion method.The strain was identified Brevibacillus laterosporus after physiological biochemical characteristic experiments,sequencing of 16S rDNA and cluster analysis,named S62-9.

Optimization of an Antimicrobial Peptide R-1 Production by Brevibacillus laterosporus Lh-1 / 微生物学通报

To improve and optimize marine antimicrobial peptide R-1 production by a newly isolated Brevibacillus laterosporus Lh-1, Plackett-Burman (PB) design and response surface methodology (RSM) using central composite design was adopted in culture conditions. MINITAB 15.0 was used for planning the experiments, data analysis, contour diagrams and response optimizations. In this study, PB design was undertaken to evaluate the effects of the fifteen factors. By the statistical regression analysis, the significant factors affecting the novel antimicrobial peptide R-1 in submerged fermentation by Br. laterosporus Lh-1 were determined as follows: glucose, peptone and CaCl2. Then a RSM was used to optimize the above critical internal factors, and the optical concentration of the variables were deter-mined as: 15.72 g/L glucose, 6.01 g/L peptone and 3.29 g/L CaCl2. The content of R-1 was increased from 82.15 kU/mL to 116.27 kU/mL.