Enrichment of hydrogen-oxidizing bacteria with nitrate recovery as biofertilizers in the mixed culture. (October 2020)

• Record Type: Journal Article
• Authors: Zhang, Wei; Niu, Yun; Li, Yong-Xin; Zhang, Fang; Jianxiong Zeng, Raymond
• Is Part Of: Bioresource technology. Volume 313(2020)
• Publication Date: 2020-10
• Subjects: Hydrogen-oxidizing bacteria -- Biofertilizer -- Mixed culture -- Nitrate -- Continuous mode -- Azospirillum; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2020.123645
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: HOB as biofertilizers are successfully enriched with nitrate at HRT of 10 h. Azospirillum as a reported biofertilizing HOB dominates in mixed cultures (84.89%). The dominated species is Azospirillum lipoferum strain DSM 1691 (72.41%). 1-aminocyclopropane-1-carboxylate conversion rate of enriched HOB is 430 nmol/mg/h. The phosphate solubilization ability of enriched HOB is 700 mg/L. Abstract: Hydrogen-oxidizing bacteria (HOB) can utilize hydrogen and oxygen to produce valuable products in biomass, including polyhydroxyalkanoates, microbial proteins, and biofertilizers. However, the method of enriching HOB as biofertilizers from mixed culture remains unknown. In this study HOB were enriched with nitrate as nitrogen source at a hydraulic retention time of 10 h. The nitrate consumption rate was 120 mgN/L/d or 16 mg N/g VSS/h, which was comparable to those of denitrification using organic carbon or hydrogen. The percentage of Azospirillum (dominated genus, reported biofertilizing HOB) was 84.89% and the dominated species was Azospirillum lipoferum strain DSM 1691. Furthermore, the enriched HOB had the abilities of 1-aminocyclopropane-1-carboxylate conversion and phosphate solubilization, the functions of biofertilizers. This is the first report on the enrichment of biofertilizing HOB from mixed culture. Meanwhile, the enriched HOB can recover nitrate from wastewater without any secondary nitrogen pollution, extending HOB application for resource recovery from wastewater.