Isolation, characterization and beneficial effects of rice associated plant growth promoting bacteria from Zanzibar soils

Abstract

This study was undertaken to isolate and characterize plant growth promoting bacteria (PGPB) occurring in four soils of Zanzibar, Tanzania as well as to evaluate their potential use as biofertilizers for rice. A total of 12 PGPB strains were isolated from rice and studied for growth characteristics, carbon/nitrogen source utilization patterns using QTS-24 kits, phosphate solubilization, indole acetic acid (IAA) production, antibiotic resistance patterns and growth at different pH, temperature and salt concentrations. All the isolates were motile and gram negative except Z3-4. Acetylene reduction activity was detected in all isolates ranging from 5.9-76.4 nmole C2H2 reduced/h x mg protein while 9 isolates produced IAA ranged from 20-90.8 mg/l. Most of the isolates showed resistance against different environmental stresses like 10-40 degrees C temperature, 0.2-1 M salt concentration and 4-8.5 pH range. Only one isolate Z2-7 formed clear zones on Pikovskaia's medium showing its ability to solubilize phosphates. Z3-2 was used to develop fluorescent antibodies to check the cross reactivity of the isolates. Inoculation of these bacterial isolates resulted in higher plant biomass, root area, and total N and P contents on Tanzanian rice variety BKN PRAT3036B under controlled conditions. Bacillus sp. Z3-4 and Azospirillum sp. Z3-1 are effective strains and, after further testing under field conditions, can be used for inoculum production of rice in Tanzania. The plant growth promoting effects of these PGPRs suggest that these can be exploited to improve crop productivity of rice in Tanzania.

Diversity of endophytic actinomycetes in mandarin grown in northern Thailand, their phytohormone production potential and plant growth promoting activity

“…Our study appears to be the first report on IAA production of various genera of actinomycetes and the very high IAA production of Nocardiopsis. Other studies have reported that bacterial and fungal isolates also showed a certain ability to produce IAA (0.6-90 µg mL −1 ), in addition to actinomycetes (Robinson et al 1998;Yasmin et al 2004;Ahmad et al 2005;Souchie et al 2007). However, based on our study, the endophytic actinomycete genus Nocardiopsis showed a very high ability to produce IAA compared with other actinomycetes, bacteria, and fungi.…”

Biological control of potato black scurf by rhizosphere associated bacteria

“…Nitrogen fixation: Pure bacterial colonies were inoculated in to NFM semisolid enrichment medium in vials and incubated at 25±2 o C for 48 h. Nitrogenase activity was measured as described by Yasmin et al (2004). Acetylene (10% v/v) was injected to the vials.…”

Potencial Biotecnológico De Rizobactérias Promotoras De Crescimento De Plantas No Cultivo De Milho E Soja

“…O crescimento vegetal pode ser promovido através de várias formas, dentre elas, fixação biológica de nitrogênio, síntese de hormônios e outras moléculas, controle biológico de patógenos e pela solubilização de nutrientes com consequente aumento da oferta de fósforo biodisponível e outros oligoelementos para absorção pelas plantas (Glick, 1995;Vessey, 2003;Adesemoye et al, 2010;Hungria et al, 2010;Canellas et al, 2015). e Saraf, 2003;Yasmin et al, 2004;Tsavkelova et al, 2005;Joseph et al, 2007;Wani et al, 2007), produção de amônia (Joseph et al, 2007; Wani e Khan, 2010), atividade antifúngica (Cazorla et al, 2007), produção de sideróforos (Wani et al, 2007) Nesse sentido, sugere-se que a inoculação de consórcios de RPCPs possa contribuir para a obtenção de um nível de nutrição adequado ao desenvolvimento do milho e da soja com menor uso de fertilizantes NPK e reduzir os impactos destes no meio ambiente. Desta forma, o presente estudo teve como objetivos, avaliar o efeito da inoculação de consórcio de bactérias do gênero Bacillus no desenvolvimento de milho e soja cultivados em casa de vegetação, quando associada à aplicação de adubação NPK em diferentes concentrações, visando sua redução e nos experimentos com soja testar a influência do local de inoculação dos microrganismos.…”

“…Bactérias do gênero Bacillus incluídas entre as RPCPs são reportadas como bactérias significantes na solubilização de fofato (Tank e Saraf, 2003;Yasmin et al, 2004;Canbolat et al, 2006;Wani et al, 2007); Bhattacharyya e Jha, 2012), produção de ácido indol-acético (Tank ISSN: 1415-7314 ISSN online: 2317 893 ENGEVISTA, V. 19, n.4, p. 890-905, Outubro 2017.…”

“…e Saraf, 2003;Yasmin et al, 2004;Tsavkelova et al, 2005;Joseph et al, 2007;Wani et al, 2007), produção de amônia (Joseph et al, 2007;Wani e Khan, 2010), atividade antifúngica (Cazorla et al, 2007), produção de sideróforos (Wani et al, 2007) e de antibióticos (Freitas e Pizzinatto, 1997). Além destas características as bactérias do gênero Bacillus apresentam outras características favoráveis à produção de inoculantes comerciais, tais como a produção de endosporos, a facilidade de manuseio e de aplicação podendo ser misturados com outros defensivos agrícolas (Freitas e Vildoso 2004).…”