Due to their abundance, they have been isolated from tissues of various plants including wheat, rice, maize, soybean, and pepper (Adegboye and Babalola 2012 El-Tarabily and Alkhajeh 2016 Goudjal et al. 2016) and broccoli (Ruzzi and Aroca 2015). Despite the fact that they are largely spread in nature and have been strongly studied largely due to their production of numerous antibacterial and antifungal compounds, only a few works have established their importance, for example, wheat (Toumatia et al. As reported by Mercado-Blanco and Bakker ( 2007), they interact with plants as free-living non-symbiotic bacteria.
This goes a long way to show the interest in the use of actinomycetes that can solubilize phosphate in phosphate-deficient soils. 2008 El-Tarabily and Sivasithamparam 2006). 2016), and solubilize phosphate (El-Tarabily et al. Actinomycetes, like other plant growth-promoting microbes, also produce phytohormone (Jog et al. The metabolites produced are diversified in their biological activities and functions such as antifungal, insecticidal, antibacterial, and antihelminthic activities. ( 2017), Adegboye and Babalola ( 2012), and other researchers have reported them to be important producers of secondary metabolites. Their filaments and ability to sporulate help them cleave strongly to the rhizospheric soil particles forming a strong bond with the plants.Īctinomycetes are a numerous and widely distributed group of soil microbes, constituting to about 10 to 50% of the soil microflora community.
Out of all rhizosphere microbes, actinomycetes are regarded to be special in plant growth promotion because they exhibit many useful traits (El-Tarabily and Alkhajeh 2016 Monteiro et al. Several actinomycetes form branching filaments and possess mycelial growth while some species produce external spores. They are mostly aerobic, but some of them can grow anaerobically. This genus is as efficient as a biofertilizer as it is as a biocontrol.Īctinomycetes are Gram-positive bacteria characterized by a genome with high G + C ratio. Compared to more focus on its biocontrol ability, less work has been done on it as a biofertilizer until recently. Some biocontrol products from this genus are already being marketed while work is still ongoing on this productive genus. These activities are highlighted and discussed in this review. This review highlights and buttresses the agricultural importance of Streptomyces through its biocontrol and plant growth-promoting activities. These genera have shown over time great potential in improving the future of agriculture.
The Streptomyces genus, which is the most abundant and arguably the most important actinomycetes, is a good source of bioactive compounds, antibiotics, and extracellular enzymes. Actinomycetes constitute a significant percentage of the soil microbial community. The need for chemical-free agricultural practices is becoming eminent due to the effects of these chemicals on the environment and human health. With the impending increase of the world population by 2050, more activities have been directed toward the improvement of crop yield and a safe environment.