Culturable Yeasts as Biofertilizers and Biopesticides for a Sustainable Agriculture: A Comprehensive Review

Abstract

The extensive use of synthetic fertilizers and pesticides has negative consequences in terms of soil microbial biodiversity and environmental contamination. Faced with this growing concern, a proposed alternative agricultural method is the use of microorganisms as biofertilizers. Many works have been focused on bacteria, but the limited literature on yeasts and their potential ability to safely promote plant growth is gaining particular attention in recent years. Thus, the objective of this review is to highlight the application of yeasts as biological agents in different sectors of sustainable agricultural practices through direct or indirect mechanisms of action. Direct mechanisms include the ability of yeasts to provide soluble nutrients to plants, produce organic acids and phytohormones (indole-3-acetic acid). Indirect mechanisms involve the ability for yeasts to act as biocontrol agents through their high antifungal activity and lower insecticidal and herbicidal activity, and as soil bioremediating agents. They also act as protective agents against extreme environmental factors by activating defense mechanisms. It is evident that all the aspects that yeasts offer could be useful in the creation of quality biofertilizers and biopesticides. Hence, extensive research on yeasts could be promising and potentially provide an environmentally friendly solution to the increased crop production that will be required with a growing population.

Soil Bacteria to Regulate Phoebe bournei Seedling Growth and Sustainable Soil Utilization under NPK Fertilization

“…Fertilization level, type, duration, and application method can individually and/or in concert change soil physical and chemical properties and, subsequently, affect soil bacteria species and diversity [17,35]. In the present experiment, NPK fertilizer acidized the soil and increased its nutrient content, resulting in the enrichment of some soil bacterial growth along with a reduction in their diversity; these results support previous observations [17][18][19]. Soil bacterial diversity under three-factor fertilization was higher than two-and single-factor fertilization, indicating that three-factor fertilization provided the most balanced nutrients for P. bournei seedlings' soil bacteria and satisfied the growth and metabolism requirements of more bacteria types, a keeping high diversity level.…”

“…Soil bacteria can reflect changes in soil in time, such as soil nutrients and pH value, and can temporarily reflect the quality of soil [18,19,28,47]. With a relative abundance of more than 1%, Bacteroidetes was only used as the marker phyla species for NPK threefactor fertilization, while there was no marker phyla species for two-and single-factor fertilization, indicating that the phyla species could not be used as the marker species for NPK fertilization.…”

“…Research results have indicated that the combined application of NPK fertilizer has no significant effect on soil bacterial diversity [16], while others have argued that it could have a diversity reduction effect [17]. However, inorganic fertilizer can change nutrient-rich and nutrient-poor bacteria in soil, which their relative abundance can be used as a microbial index to indicate and predict soil nutrient content [18,19]. Studying the influence of fertilization on changing soil bacterial community diversity and abundance is of importance in regulating soil microbial community structure, improving plant productivity, and promoting the sustainable utilization of soil.…”

Long-term fungus-plant co-variation from multi-site sedimentary ancient DNA metabarcoding in Siberia

“…Soil yeast can serve both as biotoxins (Santos et al, 2004;Compant et al 2005) or growth promoters for plants (Nassar et al, 2005;El-Tarabily and Sivasithamparam, 2006). It is likely that in Siberian soils, yeasts either function as plant parasites (Hernández-Fernández et al, 2021) or as biodegraders, as after a period of high yeast abundance, we detect a decrease in woody taxa. A better understanding of modern mutualistic and parasitic interactions in Siberian tundra and taiga soils will help to solve this research gap.…”

Composted Municipal Green Waste Infused with Biocontrol Agents to Control Plant Parasitic Nematodes—A Review

“…Some of their positive effects could be due to the provision of soluble nutrients and the production of different phytohormones. Biological control is another mechanism in which antagonistic microorganisms and enzymes that directly contribute to plant growth act as biostimulants [49].…”