Bioremediation of environmental wastes: the role of microorganisms

The growing rate of urbanization and industrialization has led to an increase in several types of pollution caused by the release of toxic chemicals to the environment. This is usually perpetuated by the manufacturing industry (e.g. detergent and dye), agricultural sectors (e.g. fertilizers and pesticides), mining industry (e.g. cyanide and sulphuric acid) and construction companies (e.g. cement and metals). These pollutants have adverse effects on the health of plants, animals, and humans. They also lead to the destruction of the microbial population in both aquatic and the terrestrial regions, and hence, have necessitated the need for remediation. Although different remediation methods, such as the physical and chemical methods, have been adopted for years, however, the drawbacks and challenges associated with them have promoted the use of an alternative which is bioremediation. Bioremediation involves using biological agents such as plants and microbes to remove or lessen the effects of environmental pollutants. Of the two, microbes are more utilized primarily because of their rapid growth and ability to be easily manipulated, thus enhancing their function as agents of bioremediation. Different groups of bacteria, fungi and algae have been employed to clean up various environmental pollutants. This review discusses the types, mechanisms, and factors affecting microbial bioremediation. It also recommends possible steps that could be taken to promote the use of microbes as bioremediation agents

Plant disease management : leveraging on the plant-microbe-soil interface in the biorational use of organic amendments

Agriculture is faced with many challenges including loss of biodiversity, chemical contamination of soils, and plant pests and diseases, all of which can directly compromise plant productivity and health. In addition, inadequate agricultural practices which characterize conventional farming play a contributory role in the disruption of the plant-microbe and soil-plant interactions. This review discusses the role of organic amendments in the restoration of soil health and plant disease management. While the use of organic amendments in agriculture is not new, there is a lack of knowledge regarding its safe and proper deployment. Hence, a biorational approach of organic amendment use to achieve sustainable agricultural practices entails the deployment of botanicals, microbial pesticides, and organic minerals as organic amendments for attaining plant fitness and disease suppression. Here, the focus is on the rhizosphere microbial communities. The role of organic amendments in stimulating beneficial microbe quorum formation related to the host-plant-pathogen interactions, and its role in facilitating induced systemic resistance and systemic-acquired resistance against diseases was evaluated. Organic amendments serve as soil conditioners, and their mechanism of action needs to be further elaborated to ensure food safety

Strategies to enhance the use of endophytes as bioinoculants in agriculture

The findings on the strategies employed by endophytic microbes have provided salient information to the researchers on the need to maximally explore them as bio-input in agricultural biotechnology. Biotic and abiotic factors are known to influence microbial recruitments from external plant environments into plant tissues. Endophytic microbes exhibit mutualism or antagonism association with host plants. The beneficial types contribute to plant growth and soil health, directly or indirectly. Strategies to enhance the use of endophytic microbes are desirable in modern agriculture, such that these microbes can be applied individually or combined as bioinoculants with bioprospecting in crop breeding systems. Scant information is available on the strategies for shaping the endophytic microbiome; hence, the need to unravel microbial strategies for yield enhancement and pathogen suppressiveness have become imperative. Therefore, this review focuses on the endophytic microbiome, mechanisms, factors influencing endophyte recruitment, and strategies for possible exploration as bioinoculants

The nexus between plant and plant microbiome : revelation of the networking strategies

The diversity of plant-associated microbes is enormous and complex. These microbiomes are structured and form complex interconnected microbial networks that are important in plant health and ecosystem functioning. Understanding the composition of the microbiome and their core function is important in unraveling their networking strategies and their potential influence on plant performance. The network is altered by the host plant species, which in turn influence the microbial interaction dynamics and co-evolution. We discuss the plant microbiome and the complex interplay among microbes and between their host plants. We provide an overview of how plant performance is influenced by the microbiome diversity and function