Isolation and Identification of Culturable Bacteria from South China Seawater and Preliminary Screening of Marine Biocontrol Bacteria

• Published in: Microorganisms (Basel) 2023-12, Vol.11 (12), p.2933
• Main Authors: Guan, Limei, Wang, Hongxiu, Chen, Junhui, Yang, Feiying, Yang, Jian, Li, Jianghuai, Jin, Liang
• Format: Article
• Language: English
• Subjects: Agricultural production; antagonistic bacteria; Anthrax; Antifungal activity; antimicrobial fungi; Bacilli; Bacteria; bacterial diversity; Bioengineering; Biological control; Botrytis cinerea; Chemical analysis; culturable bacteria; Disease control; Environmental aspects; Fermentation; Fruits; Fungi; Fungicides; Fusarium oxysporum; Gammaproteobacteria; Gene amplification; Genetic aspects; Identification and classification; Marine bacteria; Marine microorganisms; marine water; Metabolic pathways; Microorganisms; Morphology; Natural products; Pesticides; Pests; Phylogenetics; phytopathogenic fungi; Plant diseases; Rice; Sea-water; Seawater; Sodium chloride; Strains (organisms); Water analysis; Water sampling
• ISSN: 2076-2607; 2076-2607
• DOI: 10.3390/microorganisms11122933

Marine microorganisms have evolved special metabolic pathways to produce numerous bioactive substances with novel structures and unique functions. This study analyzed the diversity of culturable bacteria in marine water samples from the South China Sea and screened the isolated bacteria with pathogenic fungi. A total of 200 culturable strains of 72 different bacteria were obtained from 56 water samples from the South China Sea. They belonged to three phyla and four classes, namely Gammaproteobacteria, Alphaproteobacteria, Bacilli and Actinomycetia. Bacilli was the dominant class, comprising up to 59.72%, followed by Gammaproteobacteria (20.83%). , , and were the most dominant genera. Among these strains, HY-88 and HY-91 encoding C, B and I genes were selected and identified as . The respective inhibition rates of the HY-88 caused by plate confrontation against , , , and were 90.91%, 54.29%, 52.17% and 51.72%, in comparison with HY-91 86.36%, 48.57%, 47.83% and 34.48%. In addition, the supernatant of HY-88 showed a lesion inhibition rate of 74.5%, which was significantly higher than HY-91 (60.55%). In addition, HY-88 and HY-91 showed strong antifungal activity to on detached Shine Muscat grapes. Tolerance tests showed that the HY-88 and HY-91 grew at 10-40 °C, 7-10% NaCl and pH 3-11. HY-88 and HY-91 could inhibit various fungal plant diseases, which lays a foundation for the development of new biopesticides.