Laccase and Other Lignocellulose Modifying Enzymes of Marine Fungi Isolated from the Coast of India

Raghukumar, Chandralata; Raghukumar, Seshagiri; Chinnaraj, A.; Chandramohan, D.; D’Souza, Trevor M.; Reddy, C. A.

doi:10.1515/botm.1994.37.6.515

Cited by 68 publications

(31 citation statements)

References 32 publications

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“…We have earlier reported fungi from marine habitats capable of producing lignin-modifying enzymes [22,23]. The co-production of endoxylanase, -Dxylosidase and -L-arabinofuranosidase in a cellulase-free enzyme system by isolate # 3 from marine habitats with a potential in biobleaching, indicates the importance of marine fungi in biotechnological applications.…”

Section: Discussionmentioning

confidence: 99%

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Xylanases of marine fungi of potential use for biobleaching of paper pulp

Raghukumar

Muraleedharan

Gaud

et al. 2004

J IND MICROBIOL BIOTECHNOL

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Microbial xylanases that are thermostable, active at alkaline pH and cellulasefree are generally preferred for biobleaching of paper pulp.. We screened obligate and facultative marine fungi for xylanase activity with these desirable traits.Several fungal isolates obtained from marine habitat showed alkaline xylanase activity. The crude enzyme from NIOCC isolate # 3 (Aspergillus niger) with high xylanase activity, cellulase-free and unique properties containing 580 U L -1 of xylanase, could bring about bleaching of sugarcane bagasse pulp by a 60 min treatment at 55 o C, resulting in a decrease of 10 kappa numbers and a 30% reduction in consumption of chlorine during bleaching process. The culture filtrate showed peaks of xylanase activity at acidic pH (3.5) and alkaline pH (8.5). When assayed at pH 3.5 optimum activity was detected at 50 o C with a second peak of activity at 90 o C. When assayed at pH 8.5 optimum activity was seen at 80 o C. The crude enzyme was thermostable at 55 o C for at least 4 h and retained about 60% of the activity. Gel filtration of the 50-80% ammonium sulfate precipitatedfraction of the crude culture filtrate separated into two peaks of xylanase having specific activities of 393 and 2457 U mg -1 protein. The two peaks showing xylanase activities had molecular masses of 13 and 18 kDa. Zymogram analysis of xylanase of crude culture filtrate as well as the 50-80% ammonium sulphateprecipitated fraction showed two distinct xylanase activity bands on native PAGE The crude culture filtrate also showed moderate activities of -xylosidase and -L-arabinofuranosidase which could act synergistically with xylanase in attacking xylan. This is the first report showing potential application of crude culture filtrate of a marine fungal isolate possessing thermostable, cellulase-free alkaline xylanase activity in biobleaching of paper pulp.

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Section: Discussionmentioning

confidence: 99%

“…Isolation of fungi was carried out as described earlier by surface sterilization of detritus using 0.5% sodium hypochlorite solution for 2 min, followed by two washings with sterile sea water [22]. The detritus was plated on corn meal agar medium (Himedia Pvt.…”

Section: Isolation and Initial Screening Of Fungimentioning

confidence: 99%

Xylanases of marine fungi of potential use for biobleaching of paper pulp

Raghukumar

Muraleedharan

Gaud

et al. 2004

J IND MICROBIOL BIOTECHNOL

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“…Also, they could be used for decolorizing dye house effluents that are hardly decolorized by conventional sewage treatment plants [42,[211][212][213]. In addition to dye house effluents, laccases can decolorize waste waters from olive oil mills [214] and pulp mills [215,216] by removing colored phenolic compounds.…”

Section: Bioremediationmentioning

confidence: 99%

Laccases and Their Applications: A Patent Review

Kunamneni

Plou²,

Ballesteros³

et al. 2008

BIOT

276

172

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Abstract:Laccases are an interesting group of multi copper enzymes, which have received much attention of researchers in last decades due to their ability to oxidize both phenolic and non-phenolic lignin related compounds as well as highly recalcitrant environmental pollutants. This makes these biocatalysts very useful for their application in several biotechnological processes. Such applications include the detoxification of industrial effluents, mostly from the paper and pulp, textile and petrochemical industries, polymer synthesis, bioremediation of contaminated soils, wine and beverage stabilization. Laccases are also used as catalysts for the manufacture of anti-cancer drugs and even as ingredients in cosmetics. Recently, the utility of laccases has also been applied to nanobiotechnology. This paper reviews recent and important patents related to the properties, heterologous production, molecular cloning, and applications of laccases within different industrial fields as well as their potential extension to the nanobiotechnology area.

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“…Due to the non-specificity of these enzymes, other lignin-like molecules, such as PAHs, can be attacked and degraded as well (Bumpus et al 1985, Reddy 1995. Several marine fungi display ligninolytic activity and have been shown to possess lignin-modifying enzymes similar to those of terrestrial white-rot fungi (Raghukumar et al 1994, Pointing et al 1998). …”

Section: Microbial Biodegraders and Their Requirementsmentioning

confidence: 99%

Relative importance of macrofaunal burrows for the microbial mineralization of pyrene in marine sediments: impact of macrofaunal species and organic matter quality

Granberg

Hansen

Selck

2005

Mar. Ecol. Prog. Ser.

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The significance of macrofaunal burrows for microbial organic matter mineralization is well recognized. However, despite the importance of marine sediments as main sinks for organic particle-reactive contaminants such as polyaromatic hydrocarbons (PAHs), the significance of biogenic structures for microbial pollutant mineralization is largely unknown. We measured microbial mineralization of the PAH pyrene in different sediment compartments (surface, burrow and reduced bulk sediments) as a function of contamination history (uncontaminated and pyrene-exposed), macrofaunal species (Amphiura filiformis and Nereis diversicolor) and sediment organic matter quality (labile Tetraselmis sp. and refractory lignin). Sediments were exposed to combinations of the 3 factors for 43 d, after which sediment samples from the 3 compartments were incubated for radio-respirometric measurements in 14 C-pyrene-coated flasks to monitor 14 CO 2 production (i.e. pyrene mineralization) for 128 d. Pyrene exposure enhanced microbial pyrene mineralization (MPM) rates by an order of magnitude in all compartments, signifying MPM as inducible. MPM rates increased successively from reduced bulk to burrow and surface sediments in uncontaminated treatments, while MPM rates were highest in burrows when exposed to pyrene. This emphasizes the oxygen dependence of MPM and pinpoints burrows as MPM hot spots. Enrichment with labile organic matter doubled MPM rates in pyrene-exposed surface sediment, likely fertilizing MPM where oxygen is readily available. Burrow sediment MPM rates were doubled with A. filiformis, suggesting species-specific stimulation of the microbial community within the burrows. In conclusion, burrow sediment appears to be at least as important as surface sediment for microbial PAH degradation in marine sediments. Furthermore, macrofaunal biodiversity, sedimentation events and the trophic state of the system should be taken into account when the fate and effects of organic contaminants are assessed in marine systems.

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Laccase and Other Lignocellulose Modifying Enzymes of Marine Fungi Isolated from the Coast of India

Cited by 68 publications

References 32 publications

Xylanases of marine fungi of potential use for biobleaching of paper pulp

Xylanases of marine fungi of potential use for biobleaching of paper pulp

Laccases and Their Applications: A Patent Review

Relative importance of macrofaunal burrows for the microbial mineralization of pyrene in marine sediments: impact of macrofaunal species and organic matter quality

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