Isolation and Characterisation of Sulphur Oxidizing Bacteria Isolated from Hot Spring in Malaysia for Biological Deodorisation of Hydrogen Sulphide in Chicken Manure

Abstract

In this study, the isolation of sulphur oxidising bacteria (SOB) from hot spring in Malaysia was carried out in an enrichment culture using sodium thiosulphate as a sole energy and CO 2 as a sole carbon source. A total number of 80 SOB isolates were obtained from the agar plate and considered as positive SOB due to their abilities using thiosulphate for growth. All the isolates were initially screened for their fast growths in liquid medium and 13 isolates were selected for another screening process. Three SOB isolates namely isolate AH18, AH25, and AH28 were selected based on their abilities to grow faster, produce the highest sulphate ion and reducing the pH in the growth medium. The cells were Gram-negative and short rod-shaped. The effects of various variables including temperature (25-45 °C), pH (4-9), sodium thiosulphate concentrations (4-100 mM) and metabolic characteristic were evaluated on bacterial growth and their sulphur oxidation activities. The optimum pH of all the potential isolates occurred at pH 8.0. Meanwhile, the optimum temperature for isolate AH18, AH25 and AH28 occurred at 45 °C, 30 °C, and 30-45 °C, respectively. The three isolates were classified as facultative chemolithotroph with the capability of growth in thiosulphate concentration as high as 100 mM. Therefore, given the ability in the oxidation of thiosulphate, temperature and pH adaptabilities, with the metabolic flexibilities of isolates AH18, AH25, and AH28 could be a good H 2 S biological deodorizing candidate.

Effect of Cultural Conditions on Protease Production by a Thermophilic Geobacillus thermoglucosidasius SKF4 Isolated from Sungai Klah Hot Spring Park, Malaysia

“…Sharma et al [58] stated that different organic nitrogen sources, either complex or simple; inorganic sources; and amino acids, have been used as good sources of nitrogen among researchers to improve the production of protease enzyme. Nitrogen sources like yeast extract have been discovered to be good sources for maximum production of protease due to various amino acids, vitamins, and carbohydrates that are enough to support growth and enhance the metabolic functions of the bacteria [59]. This is in agreement with the findings of Khusro [45], who reported that yeast extract played a crucial role in the production of the enzyme due to the presence of important elements and growth factors for microorganisms [45].…”

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

“…The oxidation carried out by SOB resulted in the production of sulfuric acid leading to a lowering of the pH of the medium, which lead to a change in the colour of the dye from purple to yellow in broth and the resulting zone of clearance on agar plates. Hidayat et al (2017) reported a reduction in pH of the medium from 8.0 to <5.0 due to the production of sulfuric acid. Kambam et al (2015) and Ashraf et al (2018) also screened SOB on the basis of their potential to reduce the pH of the growth medium from 7.8 to ≤5.0 within 15 days of incubation and to oxidize elemental sulfur (S°), and Devi with her team screened rhizobacteria (Indira Devi et al, 2011).…”

A Novel Thermostable and Alkaline Protease Produced from Bacillus stearothermophilus Isolated from Olive Oil Mill Sols Suitable to Industrial Biotechnology

“…Accordingly, the curves obtained in this study compared with the effect of nitrogen sources showed that the use of yeast extract (1% w / v ) allowed the maximum cell growth (10.525 g/L ± 0.243) and protease production (7170 U/mL ± 113.13). In fact, yeast extract is considered as a good source for the maximum production of protease due to its richness of amino acids, various vitamins, and carbohydrates to improve both the cell growth and metabolic functions of the bacterium [ 28 ]. Evidently, the use of 3% yeast extract improved the proteolytic activity and dry weight biomass, which reached 9050 U/mL ± 212 and 11.05 g/L ± 0.12, respectively.…”