Microbes of the phytomicrobiome are associated with every plant tissue and, in combination with the plant form the holobiont. Plants regulate the composition and activity of their associated bacterial community carefully. These microbes provide a wide range of services and benefits to the plant; in return, the plant provides the microbial community with reduced carbon and other metabolites. Soils are generally a moist environment, rich in reduced carbon which supports extensive soil microbial communities. The rhizomicrobiome is of great importance to agriculture owing to the rich diversity of root exudates and plant cell debris that attract diverse and unique patterns of microbial colonization. Microbes of the rhizomicrobiome play key roles in nutrient acquisition and assimilation, improved soil texture, secreting, and modulating extracellular molecules such as hormones, secondary metabolites, antibiotics, and various signal compounds, all leading to enhancement of plant growth. The microbes and compounds they secrete constitute valuable biostimulants and play pivotal roles in modulating plant stress responses. Research has demonstrated that inoculating plants with plant-growth promoting rhizobacteria (PGPR) or treating plants with microbe-to-plant signal compounds can be an effective strategy to stimulate crop growth. Furthermore, these strategies can improve crop tolerance for the abiotic stresses (e.g., drought, heat, and salinity) likely to become more frequent as climate change conditions continue to develop. This discovery has resulted in multifunctional PGPR-based formulations for commercial agriculture, to minimize the use of synthetic fertilizers and agrochemicals. This review is an update about the role of PGPR in agriculture, from their collection to commercialization as low-cost commercial agricultural inputs. First, we introduce the concept and role of the phytomicrobiome and the agricultural context underlying food security in the 21st century. Next, mechanisms of plant growth promotion by PGPR are discussed, including signal exchange between plant roots and PGPR and how these relationships modulate plant abiotic stress responses via induced systemic resistance. On the application side, strategies are discussed to improve rhizosphere colonization by PGPR inoculants. The final sections of the paper describe the applications of PGPR in 21st century agriculture and the roadmap to commercialization of a PGPR-based technology.

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Plant Growth-Promoting Rhizobacteria: Context, Mechanisms of Action, and Roadmap to Commercialization of Biostimulants for Sustainable Agriculture.

Soil is dynamic living matrix and it is not only a critical resource in agricultural and food security but it is also towards maintenance of all life process. Pathogenic microorganisms affecting plant health are a major and chronic threat to sustainable agriculture and ecosystem stability worldwide. The chemical fertilizers used in the agriculture to increase yields, kill pathogens, pests, and weeds, have a big harmful impact on the ecosystem. Because of current public concerns about the side effects of agrochemicals, there is an increasing interest in improving the understanding of cooperative activities among plants and rhizosphere microbial populations. So, there is an urgent need of biological agents is accepted worldwide. The use of plant growth promoting Rhizobacteria (PGPR) is a better alternative to solve this problem. They play an important role to increase in soil fertility, plant growth promotion, and suppression of phytopathogens for development of ecofriendly sustainable agriculture. This review provides environment friendly approach to increase crop production and health, development of sustainable agriculture and commercialization by using of plant growth promoting rhizobacteria with global applicability.

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Plant Growth Promoting Rhizobacteria (PGPR): Current and Future Prospects for Development of Sustainable Agriculture

Biosorption and biotransformation of hexavalent chromium [Cr(VI)]: A comprehensive review

Antimicrobial activity of cinnamon and clove essential oils is widely known; however their application to polymeric materials is already limited. Based on results of their minimum inhibitory concentration against Penicillium commune and Eurotium amstelodami, cinnamon was chosen to be incorporated into cassava starch films in order to develop an active packaging. The effect of cinnamon essential oil were evaluated on antimicrobial activity, mechanical and barrier properties of films and the results were compared with those of control films (without antimicrobial agent). ANOVA (P

Cassava starch composite films incorporated with cinnamon essential oil: Antimicrobial activity, microstructure, mechanical and barrier properties

Antimicrobial activity of lactic acid bacteria against pathogenic and spoilage microorganism isolated from food and their control in wheat bread

Plant growth in agricultural soils is influenced by many abiotic and biotic factors. There is a thin layer of soil immediately surrounding plant roots that is an extremely important and active area for root activity and metabolism which is known as rhizosphere. The rhizosphere concept was first introduced by Hiltner to describe the narrow zone of soil surrounding the roots where microbe populations are stimulated by root activities. A large number of microorganisms such as bacteria, fungi, protozoa and algae coexist in the rhizosphere. Bacteria are the most abundant among them. Plants select those bacteria contributing most to their fitness by releasing organic compounds through exudates creating a very selective environment where diversity is low. Since, bacteria are the most abundant microorganisms in the rhizosphere, it is highly probable that they influence the plants physiology to a greater extent, especially considering their competitiveness in root colonization. The present review deals with the following topics: Plant growth promoting rhizobacteria (PGPR), occurrence of PGPR, nitrogen fixation by PGPR, Bacillus species, Pseudomonas species, Production of plant growth promoting substances by PGPR isolates, PGPR as biocontrol agent and antagonistic activity of PGPR isolates against phytopathogens.

	 

	Key words: Biocontrol, plant growth promoting rhizobacteria (PGPR), Pseudomonas fluorescens, Bacillus subtilis.

https://www3.iupui.academicjournals.org/article/article1397816590_Sivasakthi et al.pdf

Biocontrol potentiality of plant growth promoting bacteria (PGPR) - Pseudomonas fluorescens and Bacillus subtilis: A review


Spoiled food may be defined as a food that has been damaged or injured so as to make it undesirable for human consumption. Bakery products are an important part of a balanced diet and a wide variety of such products can be found on supermarket shelves. However, bakery products, like many processed foods, are subject to physical, chemical and microbiological spoilage. While physical and chemical spoilage limits the shelf life of low and intermediate moisture bakery products, microbiological spoilage by bacteria, yeast and molds is the concern in high moisture products. Many industrially produced baked goods emerge from the baking process with a surface that is essentially sterile but post bake handling can quickly lead to fungal, microbial surface contamination as a result of exposure to airborne contaminants as well as equipment contact. This present review is focused on the microbial spoilage of bakery products and its control by preservatives. This review assesses the following topics: economical importance of bakery products, microbial spoilage of bakery products, physical factors affecting microbial growth, control of microbial growth in bakery products by using chemical preservatives and biopreservatives.

Microbial Spoilage of Bakery Products and Its Control by Preservatives

Seas and oceans represent a big store for beneficial algae It is a real fact that the importance of marine organisms as a source of new substances is growing With marine species comprising approximately a half of the total global biodiversity, the sea offers an enormous resource for novel compounds and it is classified as the largest remaining reservoir of natural molecules to be evaluated for drug activity A very different kind of substances have been obtained from marine organisms among other reasons because they are living in a very exigent, competitive and aggressive surrounding very different in many aspects from the terrestrial environment, a situation that demands the production of quite specific and potent active molecules The present review is focusing on the following topics: Seaweeds in India, nutritional and medicinal values of seaweeds, antimicrobial activity of seaweeds and uses of seaweeds

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Pharmacological Importance of Seaweeds: A Review

Plant growth-promoting rhizobacteria (PGPR) are free-living, soil-borne bacteria, which enhance the growth of the plant either directly or indirectly. In the present study, Pseudomonas fluorescens and Bacillus subtilis isolates were isolated and characterized by Gram staining, motility test, plating on selective medium and performing biochemical tests. The Pseudomonas fluorescens isolates were designated as PF -1 to PF - 10 and Bacillus subtilis population was designated as BS - 1 to BS - 10. The efficiency of Pseudomonas fluorescens and Bacillus subtilis for IAA production, Gibberellic acid production, Siderophore production and Phosphate solubilization was estimated. The maximum Indole acetic acid (IAA) and Gibberellic acid (GA ) 3 production by Pseudomonas fluorescens was recorded by the isolate PF - 8 and the minimum production was observed in PF - 4 isolate. The IAA production, Gibberellic acid production and siderophore production by Bacillus subtilis was low when compared to Pseudomonas fluorescens. The maximum phosphate solubilization was recorded by the isolate BS - 8 and the phosphate solubilization by Pseudomonas fluorescens was very low.

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Production of plant growth promoting substance by Pseudomonas fluorescens and Bacillus subtilis isolates from paddy rhizosphere soil of Cuddalore district, Tamil Nadu, India.

Spirulina can play an important role in human and animal nutrition, environmental protection through wastewater recycling and energy conservation. The present review was focused on the various characteristics of Spirulina platensis. Spirulina is rich in proteins (60-70%), vitamins and minerals used as protein supplement in diets of undernourished poor children in developing countries. One gram of Spirulina protein is equivalent to one kilogram of assorted vegetables. The amino acid composition of Spirulina protein ranks among the best in the plant world, more than that of soya bean. The mass cultivation of Spirulina is achieved both in fresh water and waste water. Spirulina grown in clean waters and under strictly controlled conditions could be used for human nutrition. The micro alga grown in waste water is used as animal feed and provide a source of the fine chemicals and fuels. The waste water system is highly applicable in populated countries like India where wastes are generated in high quantities and pose environmental problem. The present review focused the following topics: Spirulina platensis, Isolation and occurrence of Spirulina platensis, newly formulated media for Spirulina cultivation, Phycocyanin and Medicinal properties of Spirulina platensis.

/pdf/spirulina-platensis-food-for-future-a-review-2tqsczf6q6.pdf

P. Saranraj

Papers

Biocontrol potentiality of plant growth promoting bacteria (PGPR) - Pseudomonas fluorescens and Bacillus subtilis: A review

Microbial Spoilage of Bakery Products and Its Control by Preservatives

Pharmacological Importance of Seaweeds: A Review

Production of plant growth promoting substance by Pseudomonas fluorescens and Bacillus subtilis isolates from paddy rhizosphere soil of Cuddalore district, Tamil Nadu, India.

Spirulina platensis - food for future: a review