ISSN 2320-5407 International Journal of Advanced Research (2015), Volume 3, Issue 12, 291 – 300 291 Journal homepage: http://www.journalijar.com INTERNATIONAL JOURNAL OF ADVANCED RESEARCH RESEARCH ARTICLE Efficient retting of bast fiber yielding stems by extracellular enzyme conglomerate and oxalic acid produced by a newly isolated Penicillium sp. Rajyasri Ghosh, Riya Kar, Shampa Bhattacharyya and Supriya Majumdar Post Graduate Department of Botany, Scottish Church College, 1 & 3, Urquhart Square, Kolkata – 700 006 Manuscript Info Abstract Manuscript History: Received: 14 October 2015 Final Accepted: 22 November 2015 Published Online: December 2015 Key words: Penicillium oxalicum, polygalacturonase, xylanase, retting, oxalic acid, wheat bran *Corresponding Author Rajyasri Ghosh In a screening program aimed at isolating a fungus capable of retting jute (Corchorus olitorius) and mesta (Hibiscus sabdariffa) ribbons within a short time, a fungus producing multiple extracellular enzymes such as polygalacturonase (83.28 IU/g), pectinolytic activity (42 IU/g), xylanase (117.96 IU/g), carboxymethylcellulase (9.81 IU/g) and oxalic acid (8.73mM) on wheat bran was isolated. The fungus was identified as Penicillium oxalicum on the basis of morphological characteristics. A significant feature is that xylanase activity increased >20 fold in solid state fermentation on wheat bran from that in submerged fermentation in minimal medium with birch wood xylan. Compatible pH and temperature optima of polygalacturonase and xylanase facilitated their joint action on the substrate. Thermostability of polygalacuronase , better than other strains of P.oxalicum aided in its functional capability. The boiled culture extract of P.oxalicum was found to remove significant amount of pectin from different portions of jute and mesta stem ribbons within 40h showing calcium chelating effect of oxalic acid. The culture extract possessing the functional enzymes and oxalic acid was able to remove 65-100% pectin from different portions of jute ribbons and 100% pectin from all portions of mesta ribbons releasing well separated fibres within 40h. The culture extract of the fungus on the sixth day of fermentation was able to ret whole jute and mesta ribbons within 40h producing well separated fibers. Copy Right, IJAR, 2015,. All rights reserved INTRODUCTION Jute industry is one of the major industries in West Bengal, India. The demand for fine jute fiber is increasing day by day for its use in apparels, chiefly as blends with cotton or other fibers. The quality of jute fiber depends largely on retting. Scarcity of adequate water is the main cause of improper retting. This warrants post-retting improvement of fiber at a cheap cost. The middle lamella of parenchymatous cells around fiber bundles in jute stems mainly contain pectin. Dissolution of this pectin along with other polysaccharides like xylan and carboxymethyl- cellulose is needed for release and proper separation of fibers. A combination of pectinase and xylanase and a small amount of carboxymethylcellulase therefore, has potentiality for application in various areas of textile processing like bast fibre degumming and improvement of fiber characteristics like fineness and softness ( Majumdar et al.,1991; Sharma and Sumere, 1992; Kapoor, 2001; Sharma and Satyanarayana, 2005; Tahir et al., 2011). Sreenath et al. (1996) reported that Jute/Cotton blended fabrics could be smoothened with enzyme combination of pectinase and xylanase. The galacturonic acid residues of pectin aggregate with Ca + + that crosslink pectin chains to each other. The presence of calcium reduces