Abstract
Organic amendment is important for promoting soil quality through increasing soil fertility and soil microbes. This study evaluated the effectiveness of using liquid food waste material (LFM) as a microbial resource, by analyzing the microbial community composition in LFM, and by isolating plant growth-promoting bacteria (PGPB) from the material. High-throughput sequencing of LFM, collected every month from May to September 2018, resulted in the detection of >1000 bacterial operational taxonomic units (OTUs) in the LFM. The results showed that Firmicutes was abundant and most frequently detected, followed by Proteobacteria and Actinobacteria. Of the culturable strains isolated from LFM, almost all belonged to the genus Bacillus. Four strains of PGPB were selected from the isolated strains, with traits such as indole acetic acid production and 1-aminocyclopropane-1-carboxylic acid deaminase activity. Lettuce growth was improved via LFM amendment with PGPB, and Brassica rapa showed significant differences in root biomass when LFM amendment was compared with the use chemical fertilizer. Field experiments using LFM showed slight differences in growth for Brassica rapa, lettuce and eggplant, when compared with the use of chemical fertilizer. LFM is a useful microbial resource for the isolation of PGPB, and its use as fertilizer could result in reduced chemical fertilizer usage in sustainable agriculture.
Highlights
Plant growth-promoting microorganisms (PGPM) are broadly accepted to enhance crop production [1]
The bacterial isolation from the liquid food waste material (LFM) was performed via standard methods, through the serial dilution plating technique
31 strains were randomly selected, and 11 out of those 31 strains were examined for plant growth-promoting (PGP)
Summary
Plant growth-promoting microorganisms (PGPM) are broadly accepted to enhance crop production [1]. Plant growth-promoting microorganisms enhance plant growth and development through a variety of functions, encompassing the increase of macro-nutrient availability to the host plant by assembly of growth-promoting chemicals [2], nitrogen fixation [3], solubilization of inorganic phosphate and mineralization of organic phosphate [4], production of different types of phytohormones-like organic compounds [5,6] and biological control of phytopathogens by synthesizing antibiotics and/or competing with harmful microorganisms [7,8]. The continuous use of PGPM could lead to it replacing pesticides and chemical fertilizers [9]. On another front, the overuse of chemical fertilizers and continuous agricultural activities results in the deterioration of soil quality [10,11]. The associated loss of soil health, fertility and nutrient status leads to continuous input requirements. Overreliance on inorganic fertilizers stretches the economics of the farming community, and leads to consumption of available non-renewable
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
