Abstract
Microcystin-LR (MC-LR) is the most toxic and frequently detected monocyclic heptapeptide hepatotoxin produced by cyanobacteria, which poses a great threat to the natural ecosystem and public health. It is very important to seek environment-friendly and cost-efficient methods to remove MC-LR in water. In this study, the MC-degrading capacities of a novel indigenous bacterial community designated as YFMCD4 and the influence of environmental factors including various temperatures, MC concentrations and pH on the MC-degrading activities were investigated utilizing high-performance liquid chromatography (HPLC). In addition, the MC-degrading mechanism of YFMCD4 was also studied using HPLC coupled with a mass spectrometry equipped with electrospray ionization interface (HPLC-ESI-MS). The data showed MC-LR was completely removed at the maximum rate of 0.5 µg/(mL·h) under the optimal condition by YFMCD4. Two pure bacterial strains Alcaligenes faecalis and Stenotrophomonas acidaminiohila were isolated from YFMCD4 degraded MC-LR at a slower rate. The MC-degrading rates of YFMCD4 were significantly affected by different temperatures, pH and MC-LR concentrations. Two intermediates of a tetrapeptide and Adda appeared in the degradation process. These results illustrate that the novel YFMCD4 is one of the highest effective MC-degrading bacterial community, which can completely remove MC-LR and possesses a significant potential to treat water bodies contaminated by MC-LR.
Highlights
Cyanobacterial harmful algal blooms (CyanoHABs) have proliferated worldwide because of eutrophication and climate change [1,2,3,4]
Two pure bacterial strains designated YFMCD4-1 and YFMCD4-2 were isolated from the bacterial community YFMCD4 and identified according to 16S rRNA gene sequences
A novel native effective MC-degrading bacterial community YFMCD4 was obtained from Lake
Summary
Cyanobacterial harmful algal blooms (CyanoHABs) have proliferated worldwide because of eutrophication and climate change [1,2,3,4]. Oscillatoria, and Nostoc during CyanoHABs threaten public health and have become a serious global problem due to their extreme toxicities, which have attracted global attention [3,5]. MCs are a group of monocyclic heptapeptide hepatotoxins with a common genetic structure cyclo-(D-Ala-X-D-MeAsp-Z-Adda-D-Glu-Mdha-), where X and Z represent variable L-amino acids, and. Adda is the b-amino acid residue of 3-amino-9-methoxy-2,6,8-trimethyl-10-phenyldeca-4,6-dienoic acid. MC-LR is harmful to different organs including liver, intestine, colon, brain, kidney, lung, heart and reproductive system because it can inhibit the activities of protein phosphatases and affect the regulation of miRNA expression in these systems [9,10]. To reduce MC-LR risks, the World Health Organization (WHO) has proposed a provisional guideline of 1 μg/L MCs in drinking water and this guideline level has been adopted in many countries such as USA, Australia, and China [13]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
