Status of the biopesticide market and prospects for new bioherbicides

Self-assembled thymol-betaine co-crystals with controlled release and hygroscopic properties as green preservatives for aflatoxin prevention

Mycotoxins are representative contaminants causing food losses and food safety problems worldwide. Thymol can effectively inhibit pathogen infestation and aflatoxin accumulation during grain storage, but high volatility limits its application. Here, a thymol-betaine co-crystal system was synthesized through grinding-induced self-assembly. The THY-TMG co-crystal exhibited excellent thermal stability with melting point of 91.2 °C owing to abundant intermolecular interactions. Remarkably, after 15 days at 30 °C, the release rate of thymol from co-crystal was only 55%, far surpassing that of pure thymol. Notably, the co-crystal demonstrated the ability to bind H2O in the environment while controlling the release of thymol, essentially acting as a desiccant. Moreover, the co-crystals effectively inhibited the growth of Aspergillus flavus and the biosynthesis of aflatoxin B1. In practical terms, the THY-TMG co-crystal was successful in preventing AFB1 contamination and nutrients loss in peanuts, thereby prolonging their shelf-life under conditions of 28 °C and 70% RH.

Bacillus-based biocontrol beyond chemical control in central Africa: the challenge of turning myth into reality

Agricultural productivity in the Great Lakes Countries of Central Africa, including Burundi, Rwanda, and the Democratic Republic of Congo, is affected by a wide range of diseases and pests which are mainly controlled by chemical pesticides. However, more than 30% of the pesticides used in the region are banned in European Union due to their high toxicity. Globally available safe and eco-friendly biological alternatives to chemicals are virtually non-existent in the region. Bacillus PGPR-based biocontrol products are the most dominant in the market and have proven their efficacy in controlling major plant diseases reported in the region. With this review, we present the current situation of disease and pest management and urge the need to utilize Bacillus-based control as a possible sustainable alternative to chemical pesticides. A repertoire of strains from the Bacillus subtilis group that have shown great potential to antagonize local pathogens is provided, and efforts to promote their use, as well as the search for indigenous and more adapted Bacillus strains to local agro-ecological conditions, should be undertaken to make sustainable agriculture a reality in the region.

Why are there no widely successful microbial bioherbicides for weed management in crops?

Microbial biopesticides to control plant pathogens and insects in crops have had significant success. However, there have been relatively few successes for microbial bioherbicides in crops, despite considerable numbers of publications and commercial product introductions in this area. Marketed microbial bioherbicide products for use in agriculture have been largely unsuccessful. This article covers the potential advantages of successful microbial bioherbicides, as well as the biological and technical issues that have limited their success. Technologies to overcome the problems that have limited the success of these products are discussed. The many advantages of using killed microbial products (e.g. cell-free filtrates) over living microbial products as bioherbicides are detailed. A commercialized mycoherbicide that has been selected for in the laboratory for control of the parasitic weed Striga hermonthica is being used with some success in Africa, indicating that non-transgenic modification of the genetics of bioherbicide microbes for improved efficacy is acceptable to some regulatory authorities. Genetic modifications to improve efficacy and host range, as well as improved application technology to greatly reduce the amount of product needed are two technologies that are likely to expand the use of microbial bioherbicides in the future. © 2023 Society of Chemical Industry.

Nano-Agrochemicals as Substitutes for Pesticides: Prospects and Risks

This review delves into the mesmerizing technology of nano-agrochemicals, specifically pesticides and herbicides, and their potential to aid in the achievement of UN SDG 17, which aims to reduce hunger and poverty globally. The global market for conventional pesticides and herbicides is expected to reach USD 82.9 billion by 2027, growing 2.7% annually, with North America, Europe, and the Asia-Pacific region being the biggest markets. However, the extensive use of chemical pesticides has proven adverse effects on human health as well as the ecosystem. Therefore, the efficacy, mechanisms, and environmental impacts of conventional pesticides require sustainable alternatives for effective pest management. Undoubtedly, nano-agrochemicals have the potential to completely transform agriculture by increasing crop yields with reduced environmental contamination. The present review discusses the effectiveness and environmental impact of nanopesticides as promising strategies for sustainable agriculture. It provides a concise overview of green nano-agrochemical synthesis and agricultural applications, and the efficacy of nano-agrochemicals against pests including insects and weeds. Nano-agrochemical pesticides are investigated due to their unique size and exceptional performance advantages over conventional ones. Here, we have focused on the environmental risks and current state of nano-agrochemicals, emphasizing the need for further investigations. The review also draws the attention of agriculturists and stakeholders to the current trends of nanomaterial use in agriculture especially for reducing plant diseases and pests. A discussion of the pros and cons of nano-agrochemicals is paramount for their application in sustainable agriculture.

T6SS: A Key to Pseudomonas's Success in Biocontrol?

Bacteria from the genus Pseudomonas have been extensively studied for their capacity to act as biological control agents of disease and pests and for their ability to enhance and promote crop production in agricultural systems. While initial research primarily focused on the human pathogenic bacteria Pseudomonas aeruginosa, recent studies indicate the significance of type VI secretion (T6SS) in other Pseudomonas strains for biocontrol purposes. This system possibly plays a pivotal role in restricting the biological activity of target microorganisms and may also contribute to the bolstering of the survival capabilities of the bacteria within their applied environment. The type VI secretion system is a phage-like structure used to translocate effectors into both prokaryotic and eukaryotic target cells. T6SSs are involved in a myriad of interactions, some of which have direct implications in the success of Pseudomonas as biocontrol agents. The prevalence of T6SSs in the genomes of Pseudomonas species is notably greater than the estimated 25% occurrence rate found in Gram-negative bacteria. This observation implies that T6SS likely plays a pivotal role in the survival and fitness of Pseudomonas. This review provides a brief overview of T6SS, its role in Pseudomonas with biocontrol applications, and future avenues of research within this subject matter.

The Registration Situation and Use of Mycopesticides in the World

Mycopesticides are living preparations that use fungal cells, such as spores and hyphae, as active ingredients. They mainly include mycoinsecticides, mycofungicides, mycoherbicides and nematophagous fungi. The utilization of fungi for controlling agricultural pests can be traced back to approximately 1880, when entomopathogenic fungi were initially employed for this purpose. However, it was not until 1965 that the world's first mycopesticide, Beauveria bassiana, was registered as Boverin® in the former Soviet Union. In past decades, numerous novel mycopesticides have been developed for their lower R&D costs, as well as the environmentally friendly and safe nature. In this review, we investigated the mycopesticides situation of registration in USA, EU, China, Canada and Australia. Superisingly, it was found that the registered mycopesticides are extremely raised in recent years. Currently, the insecticides, fungicides (nematocides) and herbicides were respectively registered 27, 53 and 8 fungal strains. This paper also analyzes the main problems currently faced by mycopesticides and offers suggestions for their future development.

Interactions between Entomopathogenic Fungi and Insects and Prospects with Glycans

Concerns regarding the ecological and health risks posed by synthetic insecticides have instigated the exploration of alternative methods for controlling insects, such as entomopathogenic fungi (EPF) as biocontrol agents. Therefore, this review discusses their use as a potential alternative to chemical insecticides and especially focuses on the two major ones, Beauveria bassiana and Metarhizium anisopliae, as examples. First, this review exemplifies how B. bassiana- and M. anisopliae-based biopesticides are used in the world. Then, we discuss the mechanism of action by which EPF interacts with insects, focusing on the penetration of the cuticle and the subsequent death of the host. The interactions between EPF and the insect microbiome, as well as the enhancement of the insect immune response, are also summarized. Finally, this review presents recent research that N-glycans may play a role in eliciting an immune response in insects, resulting in the increased expression of immune-related genes and smaller peritrophic matrix pores, reducing insect midgut permeability. Overall, this paper provides an overview of the EPF in insect control and highlights the latest developments relating to the interaction between fungi and insect immunity.

Degradation strategies of pesticide residue: From chemicals to synthetic biology

The past 50 years have witnessed a massive expansion in the demand and application of pesticides. However, pesticides are difficult to be completely degraded without intervention hence the pesticide residue could pose a persistent threat to non-target organisms in many aspects. To aim at the problem of the abuse of pesticide products and excessive pesticide residues in the environment, chemical and biological degradation methods are widely developed but are scaled and insufficient to solve such a pollution. In recent years, bio-degradative tools instructed by synthetic biological principles have been further studied and have paved a way for pesticide degradation. Combining the customized design strategy and standardized assembly mode, the engineering bacteria for multi-dimensional degradation has become an effective tool for pesticide residue degradation. This review introduces the mechanisms and hazards of different pesticides, summarizes the methods applied in the degradation of pesticide residues, and discusses the advantages, applications, and prospects of synthetic biology in degrading pesticide residues.