Growth promoting and inhibiting effects of extracellular substances of soil microalgae and cyanobacteria on Escherichia coll and Micrococcus luteus

ABSTRACT Micrococcus luteus strain K39 is an endophyte bacterium isolated from roots of the desert plant Cyperus conglomeratus collected from the Red Sea shore, Thuwal, Saudi Arabia. The draft genome sequence of strain K39 revealed a number of enzymes involved in salinity and oxidative stress tolerance or having herbicide-resistance activity.

Download Full-text

Molecular characterization of rhizobacteria isolated from walnut (Juglans regia) rhizosphere in Western Himalayas and assessment of their plant growth promoting activities

Biodiversitas Journal of Biological Diversity ◽

10.13057/biodiv/d190245 ◽

2018 ◽

Vol 19 (2) ◽

pp. 662-669

Author(s):

GH. HASSAN DAR ◽

SHAKEELA SOFI ◽

S.A. PADDER ◽

AISHA KABLI

Keyword(s):

Plant Growth ◽

Molecular Characterization ◽

Micrococcus Luteus ◽

Juglans Regia ◽

Western Himalayas ◽

Rdna Sequencing ◽

Plant Growth Promoting Activities ◽

Plant Growth Promoting ◽

Growth Promoting

Dar GH, Sofi S, Padder SA, Aisha Kabli A. 2018. Molecular characterization of rhizobacteria isolated from walnut (Juglans regia) rhizosphere in Western Himalayas and assessment of their plant growth promoting activities. Biodiversitas 19: 662-669. The present study was aimed to isolate and characterize effective bacteria from the rhizosphere of walnut (Juglans regia) grown in North Western Himalayas and assess their growth promoting potential so that they may, in future, be exploited as biofertilizers. Based on preliminary screening of 98 bacterial isolates obtained from four walnut growing districts of Kashmir valley during survey in 2015, 12 isolates were characterized morpho-biochemically and molecularly basis. On the basis of 16S rDNA sequencing they were identified as Bacillus licheniformis WI 90, B. tequilensis WI 62, B. cereus WI 36, B. subtilis strains WI 63 and WI 65, Micrococcus luteus strains WI 12, WI 41 and WI 80; M. yunnanensis strains WI 60 and WI 30 and Micrococcus sp. strains WI 11 and WI 91. The assessment of these rhizobacteria for plant growth promoting attributes revealed that B. licheniformis WI 90 possessed higher phosphorus solubilization activity (312 mg/L), followed by Micrococcus sp. WI 91 (267 mg/L) while high siderophore was produced by M. luteus WI 12 (27.2% siderophore units), followed by B. licheniformis WI 90. B. cereus strains WI 36. High IAA contents (30 µg/mL) was yielded by WI 41, followed by M. yunnanensis WI 60 (28 µg IAA/mL) while higher and statistically at par gibberellic acid was produced by B. licheniformis WI 90, Micrococcus sp. WI 91 and M. luteus WI 80. Higher chitinase enzyme activity was observed in B. subtilis WI 63 (30.5 units/mL), followed by B. tequilensis WI 62 (25.3 units/mL) and B. subtilis WI 65 (25.1 units/mL). The study revealed high plant growth promoting potential in these rhizobacteria.

Download Full-text

Plant Growth-promoting and Bio-control Activity of Micrococcus luteus Strain AKAD 3-5 Isolated from the Soybean (Glycine max (L.) Merr.) Rhizosphere

The Open Microbiology Journal ◽

10.2174/1874285802115010188 ◽

2021 ◽

Vol 15 (1) ◽

pp. 188-197

Author(s):

Anamika Dubey ◽

Ashwani Kumar ◽

Mohammed Latif Khan ◽

Devendra Kumar Payasi

Keyword(s):

Glycine Max ◽

Plant Growth ◽

Phosphate Solubilization ◽

Micrococcus Luteus ◽

Resistant Variety ◽

Bacterial Strains ◽

Control Activity ◽

Plant Growth Promoting ◽

Growth Promoting ◽

Plant Growth Promoting Traits

Background: Applications of bioinoculants for improving crop productivity may be an eco-friendly alternative to chemical fertilizers. Rhizosphere or soil-inhabiting beneficial microbes can enhance plant growth and productivity through direct and indirect mechanisms, i.e., phosphate solubilization, nutrient acquisition, phytohormone production, etc. Objective: This study is based on the hypothesis that diseases resistant plants can act as a source of potential microbes that can have good plant growth-promoting traits and bio-control potential. Methods: In this study, we have isolated the rhizobacterial strains (AKAD 2-1, AKAD 2-10, AKAD 3-5, AKAD 3-9) from the rhizosphere of a disease-resistant variety of soybean (JS-20-34) (Glycine max (L.) Merr.). These bacterial strains were further screened for various plant growth-promoting traits (phosphate solubilization, indole acetic acid (IAA), ammonia, biofilm, HCN, Exopolysaccharide (EPS), and enzyme production activity (catalase, cellulase, and chitinase)). Results: Among four, only bacterial strain AKAD 3-5 has shown plant-growth-promoting and biocontrol (98%) activity against Fusarium oxysporum. Morphological, biochemical, and molecular characterization (16S rRNA) revealed that this rhizobacterial isolate AKAD 3-5 closely resembles Micrococcus luteus (Gene bank accession: MH304279). Conclusion: Here, we conclude that this strain can be utilized to promote soybean growth under varied soil stress conditions.

Download Full-text

Exploring the Potential of Micrococcus luteus Culture Supernatant With Resuscitation-Promoting Factor for Enhancing the Culturability of Soil Bacteria

Frontiers in Microbiology ◽

10.3389/fmicb.2021.685263 ◽

2021 ◽

Vol 12 ◽

Author(s):

Marco Antonio Lopez Marin ◽

Michal Strejcek ◽

Petra Junkova ◽

Jachym Suman ◽

Jiri Santrucek ◽

...

Keyword(s):

Culture Supernatant ◽

Micrococcus Luteus ◽

Bacterial Species ◽

Amplicon Sequencing ◽

Soil Extract ◽

Soil Extracts ◽

16S Rrna Amplicon Sequencing ◽

Growth Promoting ◽

Phosphate Buffered Saline ◽

Compost Soil

A bacterial species is best characterized after its isolation in a pure culture. This is an arduous endeavor for many soil microorganisms, but it can be simplified by several techniques for improving culturability: for example, by using growth-promoting factors. We investigated the potential of a Micrococcus luteus culture supernatant containing resuscitation-promoting factor (SRpf) to increase the number and diversity of cultured bacterial taxa from a nutrient-rich compost soil. Phosphate-buffered saline and inactivated SRpf were included as controls. After agitation with SRpf at 28°C for 1 day, the soil suspension was diluted and plated on two different solid, oligotrophic media: tenfold diluted Reasoner’s 2A agar (R2A) and soil extract-based agar (SA). Colonies were collected from the plates to assess the differences in diversity between different treatments and cultivation media. The diversity on both R2A and SA was higher in the SRpf-amended extracts than the controls, but the differences on R2A were higher. Importantly, 51 potentially novel bacterial species were isolated on R2A and SA after SRpf treatment. Diversity in the soil extracts was also determined by high-throughput 16S rRNA amplicon sequencing, which showed an increase in the abundance of specific taxa before their successful cultivation. Conclusively, SRpf can effectively enhance the growth of soil bacterial species, including those hitherto uncultured.

Download Full-text