Actinobacteria From Desert: Diversity and Biotechnological Applications

Abstract

Deserts, as an unexplored extreme ecosystem, are known to harbor diverse actinobacteria with biotechnological potential. Both multidrug-resistant (MDR) pathogens and environmental issues have sharply raised the emerging demand for functional actinobacteria. From 2000 to 2021, 129 new species have been continuously reported from 35 deserts worldwide. The two largest numbers are of the members of the genera Streptomyces and Geodermatophilus, followed by other functional extremophilic strains such as alkaliphiles, halotolerant species, thermophiles, and psychrotolerant species. Improved isolation strategies for the recovery of culturable and unculturable desert actinobacteria are crucial for the exploration of their diversity and offer a better understanding of their survival mechanisms under extreme environmental stresses. The main bioprospecting processes involve isolation of target actinobacteria on selective media and incubation and selection of representatives from isolation plates for further investigations. Bioactive compounds obtained from desert actinobacteria are being continuously explored for their biotechnological potential, especially in medicine. To date, there are more than 50 novel compounds discovered from these gifted actinobacteria with potential antimicrobial activities, including anti-MDR pathogens and anti-inflammatory, antivirus, antifungal, antiallergic, antibacterial, antitumor, and cytotoxic activities. A range of plant growth-promoting abilities of the desert actinobacteria inspired great interest in their agricultural potential. In addition, several degradative, oxidative, and other functional enzymes from desert strains can be applied in the industry and the environment. This review aims to provide a comprehensive overview of desert environments as a remarkable source of diverse actinobacteria while such rich diversity offers an underexplored resource for biotechnological exploitations.

The 1-aminocyclopropane-1-carboxylic acid deaminase-producing Streptomyces violaceoruber UAE1 can provide protection from sudden decline syndrome on date palm

“…Microbial antagonists, also known as BCAs, for plant diseases prevent infection or establishment of the pathogen in host plants to control phytopathogens (Thambugala et al, 2020). Compared to other microorganisms, actinobacteria appear to withstand harsh conditions such as high temperature, salinity, and aridity (Dion, 2008;Qin et al, 2019;Xie and Pathom-aree, 2021). Therefore, we hypothesize that rhizospheric actinobacteria secreting ACCD along with a broad spectrum of antagonistic mechanisms against F. solani can substantially reduce the detrimental effect of SDS on date palm.…”

Actinobacteria Community and Their Antibacterial and Cytotoxic Activity on the Weizhou and Xieyang Volcanic Islands in the Beibu Gulf of China

“…This research demonstrated that volcanic islands are an interesting source of “rare Actinobacteria,” and many strains with cytotoxic activity could be extensively discovered from them. In future, on the one hand, new types of media and methods should be designed for the isolation of novel rare Actinobacteria ( Fang et al, 2017 ; Li et al, 2021b ; Salam et al, 2021 ; Xie and Pathom-aree, 2021 ); on the other hand, genome sequencing and analysis should be conducted to unveil a vast reservoir of biosynthetic gene clusters (BGCs) for natural products in genomes of rare Actinobacteria, which is promising for extensive mining of novel chemicals and unknown biosynthetic mechanisms ( van Bergeijk et al, 2020 ).…”

Characterization of actinophages specific to Streptomyces deserti isolated from Sohag Governorate reclaimed soils

“…Since desertification is universally acknowledged as a severe threat to biodiversity, converting desert soil into fertile, green ecosystems is a global goal. (Köberl et al, 2013) Deserts, being an unknown extreme ecosystem, are known to host various actinobacteria with biotechnology promises (Xie et al, 2021). These harsh environments are a potentially rich source of bacteria that produce new compounds with biological characteristics.…”