High Production of Chitinolytic Activity in Halophilic Conditions by a New Marine Strain of Clonostachys rosea

Abstract

Twenty-eight fungal strains have been isolated from different natural marine substrates and plate screened for their production of chitinolytic activity. The two apparent best producers, Trichoderma lixii IG127 and Clonostachys rosea IG119, were screened in shaken cultures in media containing 1% colloidal chitin, 1% yeast nitrogen base and 38‰ NaCl, for their ability to produce chitinolytic enzymes under halophilic conditions. In addition, they were tested for optimal growth conditions with respect to pH, salinity and temperature. The Trichoderma strain appeared to be a slight halotolerant fungus, while C. rosea IG119 clearly showed to be a halophilic marine fungus, its optimal growth conditions being very coherent for life in the marine environment (i.e., pH 8.0, salinity 38‰). Due to its high and relatively fast activity (258 U/L after 192 h of growth) accompanied by its halophilic behaviour (growth from 0 to 160‰ of salinity), C. rosea was selected for further studies. In view of possible industrial applications, its medium for chitinolytic enzyme production was optimized by Response Surface Methodology using 1% colloidal chitin and different concentrations of corn step liquor and yeast nitrogen base (0–0.5%). Time course of growth under optimized condition showed that maximum activity (394 U/L) was recorded after 120 h on medium containing Corn Steep Liquor 0.47% and Yeast Nitrogen Base 0.37%. Maximum of productivity (3.3 U/Lh) was recorded at the same incubation time. This was the first study that demonstrated high chitinolytic activity in a marine strain of C. rosea.

Macroalgae Derived Fungi Have High Abilities to Degrade Algal Polymers

“…For instance, C. sphaerospermum [61], C. ramotenellum [62], P. brevicompactum [63], E. nigrum [62], C. rosea [64], and R. oryzae [65] are mainly known from terrestrial environments, but they are also found in deep sea (C. sphaerospermum) [66], Dead Sea water (C. ramotenellum, P. brevicompactum) [67], river sediments (C. rosea) [68], associated with marine sponges (E. nigrum, P. brevicompactum) [69,70], bryozoan Bugula sp. (R. oryzae) [71] or with seagrasses Posidonia oceanica (C. rosea) [72]. To the best of our knowledge, this is the first study that isolated T. paraviridescens from a marine environment.…”

“…To the best of our knowledge, this is the first study that isolated T. paraviridescens from a marine environment. However, other species of Trichoderma have previously been found in marine sediments, marine sponges, mangroves, brown algae [72][73][74].…”

Production and identification of two antifungal terpenoids from the Posidonia oceanica epiphytic Ascomycota Mariannaea humicola IG100

“…In the last decades, the interest in marine and marine derived fungi has been growing due to their high e cacy in the synthesis of secondary metabolites [4,5,[10][11][12][13][14][15][16][17][18]. These organisms are also promising sources of enzymes useful in different technological applications [19][20][21]. In this context, halophilic fungi have been applied in the ne and specialty chemical elds, as well as in the production of biodiesel and bioremediation [9,[22][23][24][25][26].…”

“…In particular, fungi related to leaf district are characterized by a high content of tannic acids and represent an interesting source of new bioactive molecules [29]. A great heterogeneity of fungal colonisers from different posidonia meadows in Tyrrhenian Sea was reported [30][31][32], and their biotechnological application is still increasing [20,29]. Mariannaea humicola, belonging to Ascomycetes (Hypocreales, Nectriaceae), is generally recognised as a soil saprophytic fungus (ethimology: name refers to the soil substrate from which this fungus was isolated), [33].…”

Production and identification of two antifungal terpenoids from the Posidonia oceanica epiphytic Ascomycota Mariannaea humicola IG100.

“…In the last decades, the interest in marine and marine derived fungi has been growing due to their high e cacy in the synthesis of secondary metabolites [4,5,[10][11][12][13][14][15][16][17][18]. These organisms are also promising sources of enzymes useful in different technological applications [19][20][21]. In this context, fungi isolated in highly stressing environments (i.e.…”