Insights on bio-degumming of kenaf bast based on metagenomic and proteomics

Abstract

Background: Microbes play important roles in kanef-degumming. This study aims at identifying the key candidate microbes and proteins responsible for the degumming of kenaf bast (Hibiscus cannabinus). Kenaf bast was cut into pieces and immersed into microbia fermentation liquid collected from different sites. Fermentation liquid samples were collected at 0, 40, 110 and 150 h and then subjected to the 16S/18S rRNA sequencing analysis and isobaric tag for relative and absolute quantitation (iTRAQ) analysis. The microbial (bacterial and fungal) diversity and the differentially expressed proteins/peptides (DEPs) were identified. Results: With the prolonged degumming time, the weight loss rate increased, the bacterial diversity was decreased. [Weeksellaceae], Enterobacteriaceae and Moraxellaceae were rapidly increased at 0~40 h, and then decreased and were gradually replaced by Bacteroidaceae from 40 h to 150 h. Similarly, Chryseobacterium and Dysgonomonas were gradually increased at 0~110 h and then decreased; Acinetobacter and Lactococcus were increased at 0~40 h, followed by decrease. Bacteroides was the dominant genus at 150 h. Sequencing 18S rRNA-seq showed the gradually decreased Wallemia hederae and increased Codosiga hollandica during degumming. iTRAQ data analysis showed Rds1, and pyruvate kinase I was decreased and increased in the kanef-degumming, respectively. Other DEPs of ferredoxin I, superoxide dismutase and aconitatehydratase were identified to be related to the Glyoxylate and dicarboxylate metabolism (ko00630). Conclusions: Bacteria including Chryseobacterium, Dysgonomonas, Acinetobacter, Lactococcus and Bacteroidesand fungi like Wallemia hederae and Codosiga hollandica are key candidate microbes for kanef degumming.

Targeted Metagenomics of Retting in Flax: The Beginning of the Quest to Harness the Secret Powers of the Microbiota

“…The authors suggested that the observed enzymatic diversity and the coexistence of brown and white rot fungi indicated the existence of complex interactions between fungal species and degradation strategies. Another very recent metaproteomics study on the degumming of kenaf bast (outer-stem tissue containing fibers) probably represents the biological situation most closely related to retting (Duan et al, 2020). Here the authors analyzed kenaf bast fragments immersed into microbial fermentation liquid collected from different sites.…”

“…The operational taxonomic unit (OTU) richness values from Visi et al (2013) seem to be extremely high compared to other waterretting studies (Table 3). More recently, the evolution of both bacterial and fungal communities during water-retting of kenaf was studied using 18S rRNA gene (Duan et al, 2020). However, the results obtained concerning the Fungi kingdom must be taken with care because precisions concerning the bioinformatics analysis are not available (e.g., sub-sampling size/rarefaction) and certain inaccuracies on the taxonomic affiliation occured (e.g., confusion between the different taxonomic levels; Opisthokonta has been classified as a subkingdom and a phylum).…”

Augmented Retting Effect on Kenaf Fibers Using Alkalophilic Pectinase-Producing Bacteria in Combination with Water Solvents

“…Water retting is primarily a macero-microbial process, predominantly accomplished with specific bacterial enzymes and solvent-derived maceration [18][19][20][21]. Naturally occurring microbiota produce the desired enzymes, and the rest act as non-producers [22].…”

The transcription factor HcERF4 confers salt and drought tolerance in kenaf (Hibiscus cannabinus L.)

“…It is one of the most important natural ber producing species after cotton and jute(Giwa Ibrahim et al 2019). It is widely distributed in Asia and Africa and mainly grows in temperate to tropical regions (Duan et al 2020).…”