Performance evaluation of rhamnolipid biosurfactant produced by Pseudomonas aeruginosa and its effect on marine oil-spill remediation.

This study aimed to reveal that the effect of biosurfactant on the dispersion and degradation of crude oil. Whole genome analysis showed that Pseudomonas aeruginosa GB-3 contained abundant genes involved in biosurfactant synthesis and metabolic processes and had the potential to degrade oil. The biosurfactant produced by strain GB-3 was screened by various methods. The results showed that the surface tension reduction activity was 28.6 mN·m-1 and emulsification stability was exhibited at different pH, salinity and temperature. The biosurfactant was identified as rhamnolipid by LC-MS and FTIR. The fermentation conditions of strain GB-3 were optimized by response surface methodology, finally the optimal system (carbon source: glucose, nitrogen source: ammonium sulfate, C/N ratio:16:1, pH: 7, temperature: 30-35 °C) was determined. Compared with the initial fermentation, the yield of biosurfactant increased by 4.4 times after optimization. In addition, rhamnolipid biosurfactant as a dispersant could make the dispersion of crude oil reach 38% within seven days, which enhanced the bioavailability of crude oil. As a biostimulant, it could also improve the activity of indigenous microorganism and increase the degradation rate of crude oil by 10-15%. This study suggested that rhamnolipid biosurfactant had application prospect in bioremediation of marine oil-spill.

Characteristic microbiome and synergistic mechanism by engineering agent MAB-1 to evaluate oil-contaminated soil biodegradation in different layer soil.

Bioremediation is a sustainable and pollution-free technology for crude oil-contaminated soil. However, most studies are limited to the remediation of shallow crude oil-contaminated soil, while ignoring the deeper soil. Here, a high-efficiency composite microbial agent MAB-1 was provided containing Bacillus (naphthalene and pyrene), Acinetobacter (cyclohexane), and Microbacterium (xylene) to be synergism degradation of crude oil components combined with other treatments. According to the crude oil degradation rate, the up-layer (63.64%), middle-layer (50.84%), and underlying-layer (54.21%) crude oil-contaminated soil are suitable for bioaugmentation (BA), biostimulation (BS), and biostimulation+bioventing (BS+BV), respectively. Combined with GC-MS and carbon number distribution analysis, under the optimal biotreatment, the degradation rates of 2-ring and 3-ring PAHs in layers soil were about 70% and 45%, respectively, and the medium and long-chain alkanes were reduced during the remediation. More importantly, the relative abundance of bacteria associated with crude oil degradation increased in each layer after the optimal treatment, such as Microbacterium (2.10-14%), Bacillus (2.56-12.1%), and Acinetobacter (0.95-12.15%) in the up-layer soil; Rhodococcus (1.5-6.9%) in the middle-layer soil; and Pseudomonas (3-5.4%) and Rhodococcus (1.3-13.2%) in the underlying-layer soil. Our evaluation results demonstrated that crude oil removal can be accelerated by adopting appropriate bioremediation approach for different depths of soil, providing a new perspective for the remediation of actual crude oil-contaminated sites.

Enhanced crude oil degradation by remodeling of crude oil-contaminated soil microbial community structure using sodium alginate/graphene oxide/Bacillus C5 immobilized pellets.

Bioaugmentation (BA) of oil-contaminated soil by immobilized microorganisms is considered to be a promising technology. However, available high-efficiency microbial agents remain very limited. Therefore, we prepared a SA/GO/C5 immobilized gel pellets by embedding the highly efficient crude oil degrading bacteria Bacillus C5 in the SA/GO composite material. The optimum preparation conditions of SA/GO/C5 immobilized gel pellets were: SA 3.0%, GO 25.0 µg/mL, embedding amount of C5 6%, water bath temperature of 50°C, CaCl2 solution concentration 3% and cross-linking time 20 h. BA experiments were carried out on crude oil contaminated soil to explore the removal effect of SA/GO/C5 immobilized pellets. The results showed that the SA/GO/C5 pellets exhibited excellent mechanical strength and specific surface area, which facilitated the attachment and growth of the Bacillus C5. Compared with free bacteria C5, the addition of SA/GO/C5 significantly promoted the removal of crude oil in soil, reaching 64.92% after 30 d, which was 2.1 times the removal rate of C5. The addition of SA/GO/C5 promoted the abundance of soil exogenous Bacillus C5 and indigenous crude oil degrading bacteria Alcanivorax and Marinobacter. In addition, the enrichment of hydrocarbon degradation-related functional abundance was predicted by PICRUSt2 in the SA/GO/C5 treatment group. This study demonstrated that SA/GO/C5 is an effective method for remediating crude oil-contaminated soil, providing a basis and option for immobilized microorganisms bioaugmentation to remediate organic contaminated soil.

Pollution characteristics of groundwater in an agricultural hormone-contaminated site and implementation of Fenton oxidation process.

The groundwater polluted by an agricultural hormone site was taken as the research object, and a total of 7 groundwater samples were collected at different locations in the plant. The main pollutants in the research area were determined to be extractable petroleum hydrocarbons (C10-C40); 1,2-dichloroethane; 1,1,2-trichloroethane; carbon tetrachloride; vinyl chloride, and chloroform; the maximum content of these pollutants can reach 271 mg/L, 1.68 × 107 µg/L, 1.56 × 104 µg/L, 9.53 × 104 µg/L, 6.58 × 104 µg/L, and 4.81 × 104 µg/L, respectively. Aiming at the problems of groundwater pollution in this area, two sets of oxidation experiments have been carried out. The addition of NaHSO3 modified Fenton oxidation system was used in this contaminated water, which enhanced (2.2 ~ 46.7%) chemical oxygen demand (COD) removal rate. The highest removal rate of extractable petroleum hydrocarbons (C10-C40) can reach 99%. And the degradation rate of chlorinated hydrocarbon pollutants can reach 99% to 100%, which almost achieved the purpose of complete removal. In the NaHSO3 modified Fenton oxidation system, the addition of NaHSO3 accelerates the cycle of Fe3+/Fe2+ and ensures the continuous existence of Fe2+ in the reaction system, thereby producing more ·OH and further oxidizing and degrading organic pollutants. Our work has provided important insights for this economically important treatment of this type water body and laid the foundation for the engineering of this method.

Potential activity of Traditional Chinese Medicine against Ulcerative colitis: A review.

ETHNIC PHARMACOLOGICAL RELEVANCE: Plant materials are used as complementary and alternative therapies all over the world for the treatment of various diseases. Ulcerative colitis (UC), a chronic nonspecific inflammatory bowel disease listed as one of the modern refractory diseases by the World Health Organization, has a long course, is challenging to cure, and is prone to cause cancer. Recent years have witnessed a growing trend of applying traditional Chinese medicine (TCM) to UC. AIM OF THIS REVIEW: This review presents an overview of the pathogenesis of UC and reports the therapeutic effect of TCM on UC (including TCM prescriptions, single TCM, and treatments using TCM ingredients) to provide a theoretical basis for the use of TCM in treating UC. METHODS: We performed a collection and collation of relevant scientific articles from different scientific databases regarding TCM and its usefulness in treating UC. In this paper, the therapeutic effect of TCM is summarized and analyzed according to the existing experimental and clinical research. RESULTS: There are positive signs that TCM primarily regulates inflammatory cytokines, intestinal flora, and the immune system, and also protects the intestinal mucosa. Hence, it can play a role in treating UC. CONCLUSION: TCM has a definite curative effect in the treatment of UC. It can alleviate and treat UC in a variety of ways. We should take syndrome differentiation and treatment differentiation as the basis. With the help of modern medicine, TCM's clinical curative effects can be enhanced for the treatment of UC.

Mixture models for gene expression experiments with two species.

Cross-species research in drug development is novel and challenging. A bivariate mixture model utilizing information across two species was proposed to solve the fundamental problem of identifying differentially expressed genes in microarray experiments in order to potentially improve the understanding of translation between preclinical and clinical studies for drug development. The proposed approach models the joint distribution of treatment effects estimated from independent linear models. The mixture model posits up to nine components, four of which include groups in which genes are differentially expressed in both species. A comprehensive simulation to evaluate the model performance and one application on a real world data set, a mouse and human type II diabetes experiment, suggest that the proposed model, though highly structured, can handle various configurations of differential gene expression and is practically useful on identifying differentially expressed genes, especially when the magnitude of differential expression due to different treatment intervention is weak. In the mouse and human application, the proposed mixture model was able to eliminate unimportant genes and identify a list of genes that were differentially expressed in both species and could be potential gene targets for drug development.