title: Arsenic-Redox Transformation and Plant Growth Promotion by Purple Nonsulfur BacteriaRhodopseudomonas palustrisCS2 andRhodopseudomonas faecalisSS5.
abstract: Arsenic (As) is a well-known toxic metalloid found naturally and released by different industries, especially in developing countries. Purple nonsulfur bacteria (PNSB) are known for wastewater treatment and plant growth promoting abilities. As-resistant PNSB were isolated from a fish pond. Based on As-resistance and plant growth promoting attributes, 2 isolates CS2 and SS5 were selected and identified asRhodopseudomonas palustrisandRhodopseudomonas faecalis, respectively, through 16S rRNA gene sequencing. Maximum As(V) resistance shown byR. faecalisSS5 andR. palustrisCS2 was up to 150 and 100 mM, respectively.R.palustrisCS2 showed highest As(V) reduction up to 62.9% (6.29 ± 0.24 mM), whileR. faecalisSS5 showed maximum As(III) oxidation up to 96% (4.8 ± 0.32 mM), respectively. Highest auxin production was observed byR. palustrisCS2 andR. faecalisSS, up to 77.18 ± 3.7 and 76.67 ± 2.8μg mL-1, respectively. Effects of these PNSB were tested on the growth ofVigna mungoplants. A statistically significant increase in growth was observed in plants inoculated with isolates compared to uninoculated plants, both in presence and in absence of As.R. palustrisCS2 treated plants showed 17% (28.1 ± 0.87 cm) increase in shoot length and 21.7% (7.07 ± 0.42 cm) increase in root length, whereasR. faecalisSS5 treated plants showed 12.8% (27.09 ± 0.81 cm) increase in shoot length and 18.8% (6.9 ± 0.34 cm) increase in root length as compared to the control plants. In presence of As,R. palustrisCS2 increased shoot length up to 26.3% (21.0 ± 1.1 cm), while root length increased up to 31.3% (5.3 ± 0.4 cm), whereasR. faecalisSS5 inoculated plants showed 25% (20.7 ± 1.4 cm) increase in shoot length and 33.3% (5.4 ± 0.65 cm) increase in root length as compared to the control plants. Bacteria with such diverse abilities could be ideal for plant growth promotion in As-contaminated sites.
authors.affiliation: Department of Microbiology & Molecular Genetics, University of the Punjab, Lahore, Pakistan.
authors.forename: Kanza
authors.initials: K
authors.lastname: Batool
authors.affiliation: Department of Microbiology & Molecular Genetics, University of the Punjab, Lahore, Pakistan.
authors.forename: Fatima
authors.initials: F
authors.lastname: Tuz Zahra
authors.affiliation: Department of Microbiology & Molecular Genetics, University of the Punjab, Lahore, Pakistan.
authors.forename: Yasir
authors.identifier: 0000-0002-4787-275X
authors.initials: Y
authors.lastname: Rehman
mesh_terms: D001151:Arsenic / Q000633:toxicity*; D007210:Indoleacetic Acids / Q000378:metabolism; D010084:Oxidation-Reduction; D063245:Plant Development / Q000187:drug effects; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012241:Rhodopseudomonas / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development; D012244:Rhodospirillaceae / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development; D000070658:Vigna / Q000254:growth & development* / Q000382:microbiology; D062065:Wastewater / Q000382:microbiology
chemical_list: D001151:Arsenic; D007210:Indoleacetic Acids; D012336:RNA, Ribosomal, 16S; D062065:Wastewater