Wheat Bran Enhances the Cytotoxicity of Immobilized Alcaligenes aquatilis F8 against Microcystis aeruginosa

Abstract

Algicidal bacteria offer a promising option for killing cyanobacteria. Therefore, a new Alcaligenes aquatilis strain F8 was isolated to control Microcystis aeruginosa in this study. The algicidal activity of strain F8 was dependent on the cell density of M. aeruginosa, and the maximal algicidal rate of the free bacterium reached 88.45% within 72 h. With a view to its application to the control of M. aeruginosa in the natural environment, strain F8 was immobilized in sodium alginate beads, but immobilization of the strain decreased its algicidal rate compared to that of the free bacterium. However, addition of wheat bran to the sodium alginate matrix used to immobilize strain F8 not only eliminated the adverse effects of immobilization on the bacteria but also resulted in an 8.83% higher algicidal rate of the immobilized than free bacteria. Exclusion and recovery methods were used to identify key ingredients of wheat bran and gain insight into the mechanism underlying the observed enhancement of algicidal activity. This analysis indicated that certain factors in wheat bran, including vitamins B1, B2, B9, and E were responsible for promoting bacterial growth and thereby improving the algicidal rate of immobilized strain F8. Our findings indicate that wheat bran is able to improve the algicidal efficiency of A. aquatilis strain F8 for killing M. aeruginosa and is a good source of not only carbon and nitrogen but also vitamins for bacteria.

Revealing the characteristics of a novel bioflocculant and its flocculation performance in Microcystis aeruginosa removal

“…Clustal X software was used to perform sequences alignment 35 , and neighbor-joining phylogenetic trees were then constructed using BioEdit and Mega 4.0 36 . Additionally, the morphological characteristics of strain DT were observed by using a JEM-2010 (High Revolution) transmission electron microscope (JEOL, Japan) with an accelerating voltage of 200 kV 37 .…”

Characterization of a Novel Polymeric Bioflocculant Produced from Bacterial Utilization of n-Hexadecane and Its Application in Removal of Heavy Metals

“…produce EPS mainly composed of C and O whereas a Bacillus sp. produces EPS that mainly comprises of N and O ( Sun et al, 2015b ). Bacillus species from marine environment had reportedly produced bioflocculant composed of C, N, O, P, and even S ( Ugbenyen et al, 2014 ).…”

Encapsulation and Algicidal Properties of Fermentation Products From Vibrio brasiliensis H115

“…These results indicated that the algicidal powder was slowly released into the algal culture through the pores of the microcapsule and then acted on the algal cells. At present, the immobilization of algicidal bacteria and their potential application in controlling HABs have been studied (Jung et al, 2013;Sun et al, 2015;Wang and Coyne, 2020). To our best knowledge, this is the first report on floating microcapsules based on algicidal powder.…”

“…IRI-160 immobilized in alginate beads were used to control the growth of Karlodinium veneficum and Prorocentrum minimum (Wang and Coyne, 2020). Alcaligenes aquatilis F8 immobilized with wheat bran and sodium alginate (SA) also showed algicidal activity against Microcystis aeruginosa (Sun et al, 2015). Immobilization of algicidal bacteria has been shown to increase the cell density and the corresponding algicidal activity.…”