There is a growing demand for the efficient treatment of seaweed biomass and the production of seaweeddegrading enzymes. Fifteen algicolous fungi were isolated from the Red Sea macroalgae in Egypt and were studied for their capability of utilizing Sargassum and Palisada biomass and subsequent production of different thallus-degrading enzymes. Most of the fungi efficiently saccharified the macroalgal extracts that amounted to more than 70 % of the sugars in the unfermented macroalgal extract. Algicolous fungi fermented Sargassum through extracellular fucoidanases and alginases that were negatively correlated as revealed by principal component analysis (PCA), suggesting an antagonistic degradation of Sargassum polysaccharides. Extracellular agarases resulted in efficient fermentation of Palisada biomass. Fungi expressed also amylase and protease activities that were low or nonexistent and biomass-dependent.Amylase showed positive correlation with agarase as indicated by PCA, which suggests that the two enzymes synergistically degrade Palisada biomass. The enzymatic cocktails were also able to release reducing sugars from the powdered macroalgal thalli, indicating the importance of enzymes in the saprophytic growth of fungi. Generally, enzymatic activities and specific activities of fucoidanase, alginase, and agarase in algicolous fungi were higher than reported previously for non-algicolous fungi. Enzymatic activities of the marine brown algal pathogen Lindra thalassiae indicated that infection by this pathogen might occur through alginases. The results shed light into production of less expensive enzymatic mixtures from an understudied group of microorganisms targeting seaweeddegradation. These enzymes have many biotechnological and industrial applications as thallus maceration and protoplast isolation despite bioactivity of obtained oligosaccharides

The study of fungal species diversity from marine algae is in its infancy; as now no studies have been carried out on the distribution and diversity of fungi on the surfaces of marine macroalgae where all fungal–algal interactions tend to begin. The aim of this study was to isolate and describe the culturable part of mycobiota associated with the surface of benthic marine macroalgae (epiphytic or epibiotic fungi). This is an important step in understanding their abundance, diversity and factors influencing their variability and composition. The fungal community was dominated by Ascomycetes (89%) with Eurotiales as the most abundant fungal order followed by Capnodiales, Pleosporales, and Hypocreales, while Zygomycetes was less frequent. The nature of occurrence of fungal genera on different macroalgal hosts suggests that a mix of generalists’ framework applies to fungal epiphytes of seaweeds, but the abundance of fungal taxa varied among ecological functional groups of algae, as well as macroalgal taxonomic groups, which imply host filtering. The fungal assemblages were also characterized by temporal variation with variation in temperature, pH, and salinity as the most important abiotic factors. The structure of fungal assemblages showed high beta diversity and low similarity between hosts.

NULL

β Diversity is an ecological concept used to describe the turnover of species across a wide range of spatial and temporal scales, but such knowledge is lacking for macroalgal assemblages of the Red Sea. β Diversity patterns for Red Sea macroalgae were evaluated from different sites (Hurghada, Safaga, and Al-Quseir) and seasons across different environmental disturbances. β Diversity was studied by partitioning the total number of species (γ diversity) into additive components. Geographical heterogeneity was more important than seasonal heterogeneity in structuring macroalgae both at species and functional group levels. Species replacement as a component of β diversity produced dissimilarity in species composition and taxonomic structure. Replacement of species between sites was responsible for the presence of new functional groups of macroalgae. High β diversity and taxonomic similarity values were characteristic of the macroalgae of the Red Sea. The occurrence of small macroalgal thalli that have short life cycles induced high species replacement and subsequently high β diversity, with spatial heterogeneity and environmental gradient as drivers of β diversity. Anthropogenic disturbance at the Safaga site was suggested to induce variation of macroalgal assemblages and functional groups. Excluding rare species from the data set did not change the high values of b diversity.

The study aimed to assess the effect-combined use different of date palm composts amended with ligno-cellulolytic fungi and mineral-N on growth and N, P and K-uptake of maize plants in sandy calcareous soil. Each type of compost was applied either in organic form in dose equivalent to 100% of N fertilization (285 kg ha-1) or in organic form in combination with mineral-N (50% for each). The experiment was constructed in a complete randomized block design (CRBD). Results showed that plant height and dry weight of shoot and root of maize significantly increased as a result of the combined use of compost with mineral-N (1:1, w:w). All types of composts combined with half-dose of mineral-N was effective, however, compost that contained with Aspergillus niger + A. subsessilis + Trichoderma lanuginosus + Bacillus sp. was the best. This type of fertilization increased N-uptake shoot and root of maize more than mineral N-fertilizer by 39.73%-49%. Inaddition, the P-uptake by shoot and root of maize increased by 58.82%-156%. The addition of compost treatments to the soil increased the total N, P and K after harvesting. Regression analysis showed positive and significant linear correlation between the application rate of compost and the availability of P and K in soil.

There is a growing demand to find an effective extraction process of sulfated polysaccharides from brown algae to conserve its structure and biological activity. Fucoidan was recovered from Sargassum sp. using a hot buffer extraction process. BoxeBenhken experimental design was evaluated to study different conditions of temperature, pH and buffer: alga ratio on fucoidan yield and its sulfate content. By solving the regression equations and analyzing 3-D plots, the optimum conditions were at extraction temperature 60
C, pH 4.0, and ratio of buffer: alga 10.0 mL/g. Under these conditions, the experimental fucoidan yield, and sulfate content were 19 and 47.6% (w/w), respectively, which were in good agreement with the predicted values. The use of hot buffer extraction was efficient to obtain a high fucoidan yield with maintaining high sulfate contents. Fucoidan preparations showed variations in antioxidant properties using various antioxidant assays. Increasing reducing antioxidant activity and hydroxyl radical scavenging of fucoidan extracts was attributed to increasing total sugars, fucose, and uronic acids. The data obtained suggested that the sulfate groups might act as reductones rather than radical scavengers to contribute to the antioxidant activity of fucoidan. Additionally, proteinaceous and phenolic compounds co-extracted with crude fucoidan contributed to its antioxidant potential. Crude fucoidan demonstrated good emulsion stabilizing capacities, especially with cedar wood oil and xylene. These results suggest the use of the crude fucoidan as a good alternative to many synthetic polymers, as well as other natural polysaccharides, in several applications in the food, pharmaceutical, cosmetic, textile, paper and petroleum industries.