Hydrogen production by Pseudomonas stutzeri JX442762 isolated from thermal soil at Mettur power station, Salem district, Tamil Nadu, India

Abstract

BackgroundCarbohydrate based substrates presents a promising route of biological hydrogen production compared with chemical routes. Pure substrates including starch, sucrose as well as different organic waste materials can be used for hydrogen production. Among a large number of microbial species, strict anaerobes and facultative anaerobic chemoheterotrophs, thermoanaerobacter species are efficient producers of hydrogen. Since hydrogen is a high-energy fuel than hydrocarbon fuel, it is essential to find an alternative source. ObjectivesTo isolate hydrogen producing organism from thermal soil sample, to identify the organism as it is a cost effective way for biological hydrogen production. The hydrogen production was assessed in pure starch, sucrose and also in mango juice effluent obtained from Krishnagiri dist., to find a better substrate. MethodologyMorphological, biochemical characterization of the isolate was evaluated and finally confirmed by 16S rRNA gene sequencing. Hydrogen production was measured by simple water displacement method for the selected substrates at 70 °C, initial pH 4.0 as well as for the effluent. Results16S rRNA gene sequencing confirms the organism as Pseudomonas stutzeri which was deposited in gene bank under the accession number JX442762 and the identified strain was named as SSKVM 2012. The G + C content of the strain P. stutzeri was found to be 53 mol%. The obtained results showed that the maximum hydrogen production was observed with pure starch (255.98 ± 0.76 ml) but in sucrose it was found to be 212.82 ± 0.57 ml. The mango juice effluent showed 190.03 ± 0.81 ml hydrogen. Even though it was less when compared to hydrogen production by starch and sucrose, mango juice effluent could be a better substrate for the identified organism. ConclusionThe identified strain confirms that it can use effluent as a good source for the hydrogen production as its initial pH is 6.0 and also freely available in the environment.