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Termites are a large and important group of insects in terrestrial ecosystems that decompose lignocelluloses. Among these, Microcerotermes diversus Silvestri (Termitidae) is a destructive invasive pest in many tropical and subtropical regions. In the present study, M. diversus specimens were collected from traps in Ahvaz, Bandar Abbas, Kish, and Khark Islands. Sample suspensions were prepared in 5-ml DH2O and cultured on nutrient agar (NA) medium. All 47 representative bacterial isolates were evaluated for cellulolytic activity by growing them on cellulose Congo-red agar medium. Based on some key phenotypic characteristics, the isolates were tentatively identified at the genus level. These were confirmed by 16S rRNA analysis using a universal primer pair (P1/P6). Sequence alignments revealed that most of the isolates are novel species so far found in the termite guts. Results showed that some of the isolates are common for all surveyed areas. However, there were significant differences in their numbers and degree of cellulolytic activity. The species reported here for the first time for termites of Iran are Bacillus wiedmanii, B. paramycoides, Elizabethkingia anophelis, Lysinibacillus pakestanensis, Pseudomonas hibiscicola, Actinetobacter pitti, A. venetianus, and Ochrobactrum anthropi. [ABSTRACT FROM AUTHOR]

Cellulosic biomass is considered one of the most promising sources for the production of alternative renewable bioenergy and other valuable products. Identification and optimization of strains with high enzymatic activity that can overcome constraints imposed by the cellulosic structure is an essential step in the development of new biotechnologies. The aim of this study was to isolate and identify thermophilic (50 °C) and mesophilic (37 °C) cellulolytic bacteria from soil and leaves samples at Kerman, Iran. Degrader bacteria were isolated using serial dilution and pour plate method. Media contained carboxymethylcellulose (CMC), and filter paper was used as sources of carbon. Totally 22 mesophilic and 17 thermophilic bacterial strains which produced clear zones were further identified by morphological and biochemical tests. Screening of purified bacteria was performed to identify cellulase-producing bacteria by Congo red test. These bacteria were compared to each other based on cellulase activity, the percentage of growth, and extracellular protein amounts. The strains with the highest enzymatic activity were determined by the DNS method. The isolated US5 and US7 grew rapidly, and produced cellulase. The US5 created the largest clear zones (7 mm). Besides, these strains were selected for analysis of 16S rRNA sequence. The results showed that selected bacteria strains belong to Brevibacillus borstelensis. The B. borstelensis strains isolated in this study showed a suitable cellulase enzyme activity., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)