Exploration, antifungal and antiaflatoxigenic activity of halophilic bacteria communities from saline soils of Howze-Soltan playa in Iran

Abstract

In the present study, halophilic bacteria communities were explored in saline soils of Howze-Soltan playa in Iran with special attention to their biological activity against an aflatoxigenic Aspergillus parasiticus NRRL 2999. Halophilic bacteria were isolated from a total of 20 saline soils using specific culture media and identified by 16S rRNA sequencing in neighbor-joining tree analysis. Antifungal and antiaflatoxigenic activities of the bacteria were screened by a nor-mutant A. parasiticus NRRL 2999 using visual agar plate assay and confirmed by high-performance liquid chromatography. Among a total of 177 halophilic bacteria belonging to 11 genera, 121 isolates (68.3%) inhibited A. parasiticus growth and/or aflatoxin production. The most potent inhibitory bacteria of the genera Bacillus, Paenibacillus and Staphylococcus were distributed in three main phylogenetic clusters as evidenced by 16S rRNA sequence analysis. A. parasiticus growth was inhibited by 0.7-92.7%, while AFB and AFG productions were suppressed by 15.1-98.9 and 57.0-99.6%, respectively. Taken together, halophilic bacteria identified in this study may be considered as potential sources of novel bioactive metabolites as well as promising candidates to develop new biocontrol agents for managing toxigenic fungi growth and subsequent aflatoxin contamination of food and feed in practice.

Investigation of diverse biosynthetic secondary metabolites gene clusters using genome mining of indigenous Streptomyces strains isolated from saline soils in Iran

“…Streptomyces species isolated from the Howz-e Soltan saline soil in Iran (Latitude: 35°00’17.8”N, Longitude: 50°56’21.6”E), (geo: 35.004935, 50.939344), located 85km south of Tehran ( 11 ). Isolation of strain from soil samples, and morphologic, phenotypic, and taxonomical analyses formerly scrutinized in vitro .…”

Emerging green technologies for recovery and reuse of spent lithium-ion batteries – a review

“…197 There are many kinds of common bioleaching microorganisms, including: chemolithotrophic bacteria, heterotrophic bacteria and facultative heterotrophic bacteria. [201][202][203][204] These microorganisms are strictly controlled by temperature, humidity and environmental toxicity, thus limiting their practical application. In practical industrial applications, a variety of microbial combinations are oen used to coordinate and promote recovery.…”

The Aspergilli and Their Mycotoxins: Metabolic Interactions With Plants and the Soil Biota

“…Actinomycetes (e.g., Verheecke et al, 2014), Lactobacilli (e.g., Romanens et al, 2019), Bifidobacteria (e.g., Ghazvini et al, 2016), and Bacilli (Siahmoshteh et al, 2017) are the best-studied groups from these aspects. Several studies have conducted screening on microbial collections to find potential biocontrol isolates that inhibit mold growth, testing (1) bacteria ranging from endophytes and rhizosphere species (Wang et al, 2013); (2) traditional fermentation products (Ahlberg et al, 2017); (3) various other samples where natural interactions with toxigenic molds are far less plausible, as in halophilic soils (Jafari et al, 2018) or fish intestines (Veras et al, 2016). The effects on toxin production and the underlying mechanisms of growth and toxigenic nature are, similarly to yeasts, less understood and often not attempted to uncover.…”