海水养殖场底泥中转化硫和磷化合物的微生物及其多样性

对福建某近海养虾场底泥环境中硫和磷2种元素的微生物代谢进行了研究.结果表明,细菌代谢有机硫和无机硫产H₂S是养殖过程中造成H₂S污染的主要因素,利用半胱氨酸和硫代硫酸钠产生硫化氢的细菌数量分别为 1.6×10⁶和4.35×10³ 个·g^-1底泥;进一步研究发现,芽孢杆菌属、盐芽孢杆菌属和微杆菌属等细菌是产H₂S的优势菌群,而硫酸盐还原菌的数量较少,仅为25个·g^-1,其产H2S的作用不明显.研究还发现,转化有机磷和无机磷酸盐的优势菌群属于好氧细菌,其中分解卵磷脂的细菌和产磷酸酯酶细菌的数量分别为2.17×10⁵和 1.21×10⁶个·g^-1,转化磷酸钙的细菌数量为6.96×10³个·g^-1.本文从微生物学的角度探讨了养殖环境中硫、磷化合物的转化,提出细菌好氧代谢产H₂S是养殖环境潜在的污染因素,给出了一些改善和修复养殖环境生态的建议.

Bacterial Conversion of Sulfur-and Phosphorous-Compounds and Microbial Diversity in Sediments from a Near-Shore Marine-Cultural Region

The H₂S-producing bacteria and the phosphorous-cycling bacteria in sediments from near-shore marine-cultural region were investigated. Results indicate that the bacterial H₂S production in aerobic condition is the dominating process to produce H₂S in the sediment of cultural pond. The total counts of H₂S-producing bacteria utilizing cysteine and Na₂S₂O₃ were 1.6×10⁶ and 4.35×10³ cells g^-1 respectively. The counts of sulfate-reducing bacteria in the sediments were very little, only 2.5×10¹ g^-1. Further results show that the bacterial counts of decomposing lecithin and secreting phosphatase were 2.17×10⁵ and 1.21×10⁶ g^-1 respectively, bacterial counts of dissolving Ca₃PO₄ were 6.96×10³ g^-1. Traditional taxonomy and partial 16S rRNA gene sequencing on the H₂S-producing and phosphate-cycling bacteria indicate that most isolates could be classified as members of the following Genera: Bacillus, Halobacillus, Microbacterium, etc.