Plant Growth Promoting Rhizobacteria: Mechanism and Current Prospective

Abstract

Despite the phytotoxicity of olive-mill solid waste (OMSW) due to its high polyphenols content, OMSW have fertilizer characteristics, which make it a potential source for organic fertilization. Composting of OMSW treatment process was conducted in this study to eliminate the phytotoxicity and solve the environmental impact of this waste. Recycling of OMSW was carried out via composting of six batches of trials using equal proportions of OMSW, cow manure (C) and wheat straw (W). The treatment process was performed at two time intervals (two and five months), after each one, the recipient species (Vicia faba L.) was planted. The results showed the efficiency of composting in reducing OMSW original toxicity after two months than five months. The germination percentage and the plumule and radicle lengths of V. faba showed a significant improvement when the OMSW was composted with C at different proportions before using as soil amendments. Besides, the total biomass was noticeably increased at the high concentration of C-OMSW. Similarly, the total pigments concentration in V. faba was increased by using various composts after two months, where the highest pigment content was observed at 40% W-OMSW treatment.The maximum uptake of potassium and sodium was recorded through the application of W-OMSW compost to soil after two months. Furthermore, the C-OMSW composts showed the highest concentration of nitrogen, calcium, iron and manganese. However, the C-W-OMSW composts recorded the highest concentration of phosphorous, magnesium and copper. Finally, this study developed a low cost treatment that will enable the growers to convert OMSW into a natural nontoxic compost rich with essential nutrients which have positive effects on plants growth.

Comparative study of plant growth‐promoting bacteria on the physiology, growth and fruit quality of strawberry

“…PGPB have shown potential to promote plant growth by the release of metabolites into the rhizosphere, stimulating growth, or by inhibiting various pathogens as biocontrol agents . Moreover, they can improve plant nutrition and support plant development under natural or stressed conditions, as well as increasing yield and quality of important crops, playing a crucial role in sustainable development . Increased fruit quality, in terms of taste and nutritional value, can also have a positive impact on human health, with associated reductions in healthcare costs …”

Improving Yield and Antioxidant Properties of Strawberries by Utilizing Microbes and Natural Products

“…However, Tomic et al [9] found that the response to bacterial inoculation is cultivar-related in strawberries. These microbes were reported to improve plant nutrition and support plant development under natural or stressed conditions as well as increase yield and quality of many important crops and thus may play a crucial role in sustainable crop production in the future [10][11][12]. A small but significant body of literature also suggests that these microbes can increase strawberry fruit quality in terms of taste and nutritional value and thereby have a positive impact on human health with associated reduction of healthcare costs [13,14].…”

Studies for IAA (Indole-3-Acetic Acid) Production by Isolates H6 with Nitric Acid Mutation

“…IAA are known promote growth of auxiliary bud and bud formation, help in the apical dominance, stimulate lateral and adventitious root development and growth. Besides development, IAA were also play crucial role in leaf and flower abscission (Kundan et al 2015).Genus of PGPR could produce IAA by several pathway. Biosynthesis of IAA which are used by single bacterial strain sometimes containing more than one pathway (Patten and Glick 1996).…”

“…IAA are known promote growth of auxiliary bud and bud formation, help in the apical dominance, stimulate lateral and adventitious root development and growth. Besides development, IAA were also play crucial role in leaf and flower abscission (Kundan et al 2015).…”

“…The genera of PGPR include Azoarcus, Azobacter, Azorhizobium, Azospirillum, Azotobacter, Bacillus, Beijerinckia, Burkholderia, Chryseobacterium, Frankia, Gluconacetobacter, Herbaspirillum, Mycobacterium, Paenibacillus, Phyllobacterium, P s Sphingomonas, and Streptomyces (Vejan et al 2016). In addition, genus Acetobacter, Enterobcter, Actinobacteria, Brevibacillus, Lysinibacillus, Terribacillus and Jeotgalibacillus also included PGPR (Kundan et al 2015). …”