Pectinolytic Bacterial Consortia Reduce Jute Retting Period and Improve Fibre Quality

Abstract

Jute fibre is the second most important fibre next to cotton. It is obtained from the bark of plant through microbial retting process. Here we report optimized microbial retting protocol that can lower retting period and produce high fibre quality. A total of 451 bacterial colonies have been isolated from five jute retting water samples in Bangladesh. Higher pectinolytic bacterial isolates were predominant in the later stage of jute retting. Out of these, 168 isolates have been screened by both semi-quantitative and quantitative pectinase, xylanase and cellulase enzyme assay. Among them, 144 isolates have been selected on the basis of extra cellular enzyme activity of these three enzymes. 16 s ribosomal gene sequencing analysis identified 2 phyla-Firmicutis (80.55%) and Proteobacteria (19.45%). To check the synergistic and antagonistic effect 10 selected isolates were tested in 167 different combinations. Three best combinations were identified that lowered retting period from 18-21 days to 10 days producing high quality fibre in both laboratory and field trial. This improved retting technology can be adopted in industrial scale for the production of quality jute fibre in a controlled condition in reduced water quantity without polluting the environment.Jute, second most important natural fibre after cotton, is cultivated in East Asia and some parts of Latin America 1-3 . Jute is a bast or phloem fibre in the bark of stems, cemented together by pectin and gummy substances 4 . Commercial extraction of jute fibre is water based microbiological retting where jute bundles are submerged into slow running river water and subjected to decomposition of pectin, hemicelluloses, and other mucilaginous substances 2,5 . In this process, pectin is depolymerized by pectinases, primarily comprising four enzymes: Polygalacturonase (PG), Pectin Lyase (PNL), Pectate lyase and Pectin esterase. However, PG 6 , and PNL 7 are primary retting enzymes. In addition, xylanase makes jute fibre softer by selective removal of non-fibrous hemicelluloses without affecting strength of cellulosic fibre. Pectinolytic microorganisms having xylanase activity devoid of cellulase activity is an additional beneficial aspect to improve fibre quality 8 . The quality of fibre is largely determined by the efficiency of retting process 1,2,9,10 and various factors are responsible for proper retting as well as improved fibre quality. Most promising water based microbiological retting process mostly involves bacteria along with various fungi, protozoa, algae and diatoms 10-13 . Main aerobic retting bacteria belong to genus Bacillus viz., B. subtilis, B. polymyxa, B. mesentericus, B.pumilus, B. cereus, B. megaterium and B. macerans, initiate retting 14-18 along with large numbers of gram-negative genera such as Erwinia and Pseudomonas 9,19 . At the later stage of retting some anaerobic bacteria from genus Clostridium -Clostridium acetobutylicum, Clostridium stercorarium, Clostridium tertium come to carry on the retting process 20 . As microorganisms are the ma...

Bacteria associated with Sarcocornia neei (Lag.) With apparent hydrolytic activity and biological control from the Paraguayan dry Chaco

“…En este ensayo cualitativo los aislados bacterianos que presentaron un halo visible de hidrólisis, fueron un total de 30 (36,1%), dato similar al trabajo de Hasan et al (2020), encontraron que el 37,2% de los aislados bacterianos proveniente de Corchorus olitorius , con capacidad de producir pectinasa y xilanasa de manera conjunta. En cuanto al origen de los aislados según relación con S. neei se obtuvieron endofíticas 76,6%, las bacterias aisladas provenientes de la rizosfera 23,3% (Figura 5C).…”

Biochemical Prospects of Various Microbial Pectinase and Pectin: An Approachable Concept in Pharmaceutical Bioprocessing

“…The significant contribution of these enzymes has drawn considerable attention from different biotechnologists worldwide to enhance their potentiality by adapting several recombinant strategies ( 18 , 19 ). The commercialized pectinase enzymes are produced by either submerged fermentation (SmF) or solid-state fermentation (SSF) that varies in the use of selected fungus or bacteria ( 20 – 22 ). The SmF technique has been adopted since 1940s when the microorganisms were cultivated on liquid broth with constant agitation for the large-scale production of antibiotics and later widely applied in various industries for the production of a huge assortment of microbial metabolites ( 23 , 24 ).…”

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

“…The screening results show that both isolates were able to hydrolyze pectin; therefore, these isolates were designated as alkalophilic pectinase-producing bacteria (APPB). Even though multiple enzymes are required to degrade heterogeneous cell wall components, pectinase is the main retting enzyme determining the retting magnitude, and applications of high efficiency pectinolytic bacterial strains are advantageous in decreasing the retting period, thus enhancing fiber quality [25,43]. The quantitative multiple enzymatic activities of these isolates are presented in Figure 2.…”

“…Naturally occurring microbiota produce the desired enzymes, and the rest act as non-producers [22]. In the last few decades, several studies have tried to incorporate bacterial enzymes or direct inoculum applications, including Bacillus, Enterobacteriaceae, and Pectobacterium, or consortia to leverage the CWR [18,[23][24][25][26]. However, non-sterile niches confer a poorer degumming efficiency.…”