Hepatotoxic microcystins (MCs) are produced and released by the harmful bloom-forming cyanobacteria, which severely threaten drinking water safety and human health due to their high toxicity, widespread distribution, and structural stability. The linearized microcystinase (MlrB) further hydrolyses the poisonous linearized MCs produced by the microcystinase-catalysed MCs to form tetrapeptides. Here, the purification and activity of MlrB were investigated. The results showed that the linearized products generated by 12.5 mg/L MC-LR and MC-RR were removed by purified recombinant MlrB at a protein concentration of 1 mg/L within 30 min. The high catalytic activity of MlrB can be obtained via heterologous expression and affinity purification, which lays the foundation for further studies on the properties and mechanism of MCs biodegradation enzymes.
Purpose Although the use of microbial fertilizers is still far lower than that of chemical fertilizers in the planting industry, it has still received much attention for its non-toxic and pollution-free characteristics. Here a promising bacterial strain was successfully isolated from the tomato rhizosphere and identified as Bacillus Safensis YY-01 with 16S rDNA sequence, which was found to significantly enhance both the growth of tomato and the relative abundance of beneficial microorganisms such as Bacillus, Chaetomium, Proteobacteria, Actinobacteria, and Chloroflexi. B. Safensis YY-01 may be a strong candidate as one bacterial strain of microbial fertilizers. Methods B. Safensis YY-01 was isolated and cultured, which was used as leaf fertilizer to spray on the phylloplane of tomato every week. The effect of B. Safensis YY-01on the height, chlorophyll, and peroxidase (POD) activity of tomato was investigated, moreover, the microbial community structure of tomato rhizosphere soil was analyzed through high-throughput sequencing technology. Results Compared with the control, the height, chlorophyll A, chlorophyll B, total chlorophyll, and POD activity of tomato Haoliang No.998 were increased by 12.8%, 17.1%, 11.8%, 14.8%, and 37.5%, respectively, and yingfen No.8 were increased by 14.1%, 7.8%, 10.2%, 10.7%, and 7.3%, respectively. Further, the microbial community structure in rhizosphere soil of tomato Haoliang No.998 was analyzed and showed that the relative abundance of beneficial microorganisms such as Proteobacteria, Actinobacteria, Chloroflexi, Bacillus, and Gemmatimonadota increased significantly, and the relative abundance of tomato yingfen No.8’s Acidobacteriota, Actinobacteria, and Bacillus were also increased significantly. Conclusion A promising bacterial strain of B. Safensis YY-01 was successfully isolated, which was beneficial to both the growth of tomatoes and the relative abundance of helpful microorganisms in the rhizosphere soil of tomatoes.
Extensive use of phthalic acid esters (PAEs) as plasticizer causes diffusion into the environment, which posed a great threat to mankind. In the present study, one promising bacterial strain for biodegrading diethyl phthalate (DEP) was successfully isolated from activated sludge and characterized as Comamonas sp. USTBZA1 based on 16S rRNA sequence analysis. Under the optimal conditions of pH 7.5, 30℃ and inoculum volume ratio of 6%, initial DEP of 50 mg/L could be completely biodegrade by strain USTBZA1 within 24 h which conformed to the Gompertz model. Based on Q-TOF LC/MS analysis, monoethyl phthalate (MEP) and phthalic acid (PA) were identified as the metabolic products of DEP biodegradation by USTBZA1. Furthermore, the whole genome of Comamonas sp. USTBZA1 was analyzed to excavate PAEs catabolic genes in stain USTBZA1. There were 3 and 41 genes encoding esterase/arylesterase and hydrolase respectively which could involve in PAEs hydrolysis, and two genes regions (pht34512 and pht4253) were responsible for the conversion of PA to protocatechuate (PCA), and two genes regions (ligCBAIKJ) are involved in PCA metabolism in USTBZA1. These results substantiated that Comamonas sp. USTBZA1 had potential application in the DEP bioremediation.
High serum uric acid levels, known as hyperuricemia (HUA), are associated with an increased risk of developing gout, chronic kidney disease, cardiovascular disease, diabetes, and other metabolic syndromes. In this study, a promising bacterial strain capable of biodegrading uric acid (UA) was successfully isolated from Baijiu cellar mud using UA as the sole carbon and energy source. The bacterial strain was identified as Bacillus paramycoides-YC02 through 16S rDNA sequence analysis. Under optimal culture conditions at an initial pH of 7.0 and 38 °C, YC02 completely biodegraded an initial UA concentration of 500 mg/L within 48 h. Furthermore, cell-free extracts of YC02 were found to catalyze and remove UA. These results demonstrate the strong biodegradation ability of YC02 toward UA. To gain further insight into the mechanisms underlying UA biodegradation by YC02, the draft genome of YC02 was sequenced using Illumina HiSeq. Subsequent analysis revealed the presence of gene1779 and gene2008, which encode for riboflavin kinase, flavin mononucleotide adenylyl transferase, and flavin adenine dinucleotide (FAD)-dependent urate hydroxylase. This annotation was based on GO or the KEEG database. These enzymes play a crucial role in the metabolism pathway, converting vitamin B2 to FAD and subsequently converting UA to 5-hydroxyisourate (HIU) with the assistance of FAD. Notably, HIU undergoes a slow non-enzymatic breakdown into 2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline (OHCU) and (S)-allantoin. The findings of this study provide valuable insights into the metabolism pathway of UA biodegradation by B. paramycoides-YC02 and offer a potential avenue for the development of bacterioactive drugs against HUA and gout.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.