Characterizations of sulfur oxidizing bacteria from extensive shrimp ponds

Abstract

The aim of this study is to characterize the sulfur oxidizing bacteria (SOB) isolates from the sediments of extensive shrimp ponds for recommending the use of this group for water quality management in aquaculture. Sediment samples were collected from 12 extensive shrimp ponds located in Tra Vinh, Soc Trang, Bac Lieu, and Ca Mau provinces. To screen the potential sulfur oxidizing bacteria, medium was amended with sodium thiosulfate, and the sulfate ion production ability and sulfur oxidase enzyme activity of the isolates were measured spectrophotometrically. Results showed that 30 isolates grew on the thiosulfate agar medium. Among these, only five isolates reduced the pH of the growth medium and showed high sulfur oxidase activity and production of sulfate ion when isolates were inoculated with thiosulfate as a substrate. Physiological and biochemical tests indicated that five selected isolates were Gram negative, short rod, non-motile, non-spore forming, negative for oxidase reaction, and positive for catalase reaction. The isolates SOBTB1.1 and SOBTB6.2 showed the significantly higher sulfur oxidase activity and production of sulfate ion compared to other isolates. SOBTB6.2 isolate produced sulfate ion and exhibited higher sulfur oxidase activity at pH4-5, followed by pH6-7. It is, therefore, suggested that the SOBTB 1.1 and SOBTB6.2 could be promising sulfur oxidizers for further research and uses in aquaculture.

Characterization of sulfur-oxidizing bacteria isolated from mustard (Brassica juncea L.) rhizosphere having the capability of improving sulfur and nitrogen uptake

“…In another study, SOB (both autotrophs and heterotrophs) were isolated and screened from sulfur water having sulfur oxidation capacity in water (Koul et al, 2018). Recently, many research have been working on the isolation of SOB from different sources with having applications in divergent areas (Borse et al, 2021;Dou et al, 2022;Huynh et al, 2021;Jadhav et al, 2022;Joseph et al, 2021;Nadella et al, 2019;Shinde et al, 2022;Tajarudin et al, 2020;Updegraff et al, 2022;Xie et al, 2021), etc. The initial pH of broth decreased from 8.0 to acidic pH due to the oxidation of sodium thiosulfate to sulfate ions.…”

“…Behera et al (2014) also measured sulfide oxidase activity of their isolates and it was found in a range of 11.6-126.83 U ml −1 min −1 , which was in conformity with the present study. Huynh et al (2021) checked sulfur oxidase activity at different pHs and found maximum activity at pH 4-5.…”

“…As we know, micro‐organisms have been proved as a potential game changer in many fields including crop production and improvement of the environment. Recently, many attempts have been made to isolate and characterize SOB from many sources like aquaculture farm soil (Nadella et al, 2019), palm oil sludge (Tajarudin et al, 2020), fresh water sediment (Xie et al, 2021), processed wastewater from food industries (Borse et al, 2021), extensive shrimp ponds (Huynh et al, 2021; Joseph et al, 2021), coastal regions (Shinde et al, 2022), anchialine sinkhole of river (Updegraff et al, 2022), wastewater (Dou et al, 2022), etc. In this study, SOB were isolated from the mustard fields and their efficiency was checked in terms of N and S uptake in wheat and mustard.…”