Fusarium oxysporum f. sp. lycopersici (Fol) and Fusarium oxysporum f. sp. cubense (Foc), are the causal agent of Fusarium wilt disease of tomato and banana, respectively, and cause significant yield losses worldwide. A cost-effective measure, such as biological control agents, was used as an alternative method to control these pathogens. Therefore, in this study, six isolates of the Streptomyces-like colony were isolated from soils and their antagonistic activity against phytopathogenic fungi and plant growth-promoting (PGP) activity were assessed. The results showed that these isolates could inhibit the mycelial growth of Fol and Foc. Among them, isolate STRM304 showed the highest percentage of mycelial growth reduction and broad-spectrum antagonistic activity against all tested fungi. In the pot experiment study, the culture filtrate of isolates STRM103 and STRM104 significantly decreased disease severity and symptoms in Fol inoculated plants. Similarly, the culture filtrate of the STRM304 isolate significantly reduced the severity of the disease and symptoms of the disease in Foc inoculated plants. The PGP activity test presents PGP activities, such as indole acetic acid production, phosphate solubilization, starch hydrolysis, lignin hydrolysis, and cellulase activity. Interestingly, the application of the culture filtrate from all isolates increased the percentage of tomato seed germination and stimulated the growth of tomato plants and banana seedlings, increasing the elongation of the shoot and the root and shoot and root weight compared to the control treatment. Therefore, the isolate STRM103 and STRM104, and STRM304 could be used as biocontrol and PGP agents for tomato and banana, respectively, in sustainable agriculture.

Recently, strategies for controlling Fusarium oxysporum f. sp. lycopersici (Fol), the causal agent of Fusarium wilt of tomato, focus on using effective biocontrol agents. In this study, an analysis of the biocontrol and plant growth promoting (PGP) attributes of 11 isolates of loamy soil Bacillus spp. has been conducted. Among them, the isolates B.PNR1 and B.PNR2 inhibited the mycelial growth of Fol by inducing abnormal fungal cell wall structures and cell wall collapse. Moreover, broad-spectrum activity against four other plant pathogenic fungi, F. oxysporum f. sp. cubense race 1 (Foc), Sclerotium rolfsii, Colletotrichum musae, and C. gloeosporioides were noted for these isolates. These two Bacillus isolates produced indole acetic acid, phosphate solubilization enzymes, and amylolytic and cellulolytic enzymes. In the pot experiment, the culture filtrate from B.PNR1 showed greater inhibition of the fungal pathogens and significantly promoted the growth of tomato plants more than those of the other treatments. Isolate B.PNR1, the best biocontrol and PGP, was identified as Bacillus stercoris by its 16S rRNA gene sequence and whole genome sequencing analysis (WGS). The WGS, through genome mining, confirmed that the B.PNR1 genome contained genes/gene cluster of a nonribosomal peptide synthetase/polyketide synthase, such as fengycin, surfactin, bacillaene, subtilosin A, bacilysin, and bacillibactin, which are involved in antagonistic and PGP activities. Therefore, our finding demonstrates the effectiveness of B. stercoris strain B.PNR1 as an antagonist and for plant growth promotion, highlighting the use of this microorganism as a biocontrol agent against the Fusarium wilt pathogen and PGP abilities in tomatoes.

Antibacterial and anti-breast cancer cell line activities of Sanghuangporus sp.1 extracts

Thirty isolates of Streptomyces like colony isolated from vermicompost soils were assessed for their antagonistic and plant growth-promoting (PGP) activities. Five isolates having the best inhibitory activity against five plant pathogenic fungi, Colletotrichum gloeosporioides, C. musae, Fusarium sp. TFPK201, Fusarium sp. Foc 1699 and Pestalotia sp. were subsequently identified by 16S rDNA analysis. The selected isolates were classified in the genus Streptomyces and given the name of Streptomyces spp. SEF1, SEF8, SEF47, SEF48 and SEF49, respectively. Then, their PGP and antifungal activities were evaluated. The results showed that the selected isolates were able to produce IAA, siderophore, and amylase. Production of IAA was ranged from 14.06 to 16.59 µg/mL. The highest siderophore production was found in the isolate SEF48. Only isolates SEF47, SEF48, and SEF49 showed amylolytic activity. The culture filtrate from the tested Streptomyces spp. inhibited the fungal mycelial growth and suppressed conidial germination, but their inhibition ability was different. Interestingly, the application of all selected culture filtrates before disease infection significantly decreased tomato Fusarium wilt disease incidence and severity. However, only Streptomyces sp. SEF47 could significantly reduce the disease incidence and severity when it was applied after the disease infection. Moreover, this research found the plant growth-promoting ability of the culture filtrate of selected isolates on tested tomatoes. The Streptomyces sp. SEF47 provided a significant ability for controlling all tested plant pathogenic fungi and promoting plant growth. Therefore, Streptomyces sp. SEF47 could be considerable biocontrol and PGP agent used in sustainable agriculture.