Dinabandhu Sahoo

Bioethanol production from Gracilaria verrucosa, a red alga, in a biorefinery approach.

In this study, Gracilaria verrucosa, red seaweed has been used for production of agar and bioethanol. The algae harvested at various time durations resulted in extraction of ~27-33% agar. The leftover pulp was found to contain ~62-68% holocellulose, which on enzymatic hydrolysis yielded 0.87 g sugars/g cellulose. The enzymatic hydrolysate on fermentation with Saccharomyces cerevisiae produced ethanol with an ethanol yield of 0.43 g/g sugars. The mass balance evaluation of the complete process demonstrates that developing biorefinery approach for exploiting Gracilaria verrucosa, a red alga, could be commercially viable.

Using marine macroalgae for carbon sequestration: a critical appraisal

There has been a good deal of interest in the potential of marine vegetation as a sink for anthropogenic C emissions (“Blue Carbon”). Marine primary producers contribute at least 50% of the world’s carbon fixation and may account for as much as 71% of all carbon storage. In this paper, we analyse the current rate of harvesting of both commercially grown and wild-grown macroalgae, as well as their capacity for photosynthetically driven CO2 assimilation and growth. We suggest that CO2 acquisition by marine macroalgae can represent a considerable sink for anthropogenic CO2 emissions and that harvesting and appropriate use of macroalgal primary production could play a significant role in C sequestration and amelioration of greenhouse gas emissions.

Seaweed tissue culture as applied to biotechnology: Problems, achievements and prospects

Advances have been made in cell and tissue culture of seaweeds to define a unique branch of in vitro techniques; however, they are lagging far behind those of land plants and have limited applications. Explants can be cultivated axenically in enriched or artificial seawater culture media, and regeneration and even callus formation are achieved. In this state of the art technique, seaweed tissue culture may be already useful for certain biotechnological applications, such as clonal propagation of seed material for mariculture. Nevertheless, the absolute control of growth and development as it is exerted in higher plant tissue culture is lacking, and it is required for more complex biotechnological applications in seaweeds. Definitively, we need appropriate cells (competent cells) to induce growth with the most effective chemical regulators in culture medium adjusted towards the addition of carbon sources. Still, free cells and protoplast isolation and regeneration in marine seaweeds constitute the most developed topic in seaweed tissue culture. The regulation of growth and development of seaweed free cell and protoplast cultures may sustain a purposeful use of techniques in the era of genomic applications.

Effect of seaweed liquid extract on growth and yield of Triticum aestivum var. Pusa Gold

The effect of seaweed liquid extract (SLE) of Sargassum wightii on germination, growth and yield of Triticum aestivum var. Pusa Gold was studied. Application of a lower concentration (20%) of SLE enhanced the percentage of seed germination, growth and yield, as measured by kernel number and seed dry weight. All growth and yield parameters were found to be highest at the 20% concentration SLE treatment. Total (100%) seed germination was observed for the 20% concentration SLE treatment, an 11% increase over the control. The present study demonstrated that seaweed liquid extract could serve as an alternative biofertilizer as is eco-friendly, cheaper, deliver substantial economic and environmental benefits to farmers.

Bioflocculation: An alternative strategy for harvesting of microalgae - An overview

Microalgae based research has been extensively progressed for the production of value added products and biofuels. Potential application of microalgae for biofuel is recently gained more attention for possibilities of biodiesel and other high value metabolites. However, high cost of production of biomass associated with harvesting technologies is one of the major bottleneck for commercialization of algae based industrial product. Based on the operation economics, harvesting efficiency, technological possibilities, flocculation of algal biomass is a superior method for harvesting microalgae from the growth medium. In this article, latest trends of microalgal cell harvesting through flocculation are reviewed with emphasis on current progress and prospect in environmental friendly bio-based flocculation approach. Bio-flocculation based microalgae harvesting technologies is a promising strategy for low cost microalgal biomass production for various applications.

Developmental Studies in Porphyra Vietnamensis : a High-Temperature Resistant Species from the Indian Coast

Porphyra vietnamensis Tanaka & Pham-Hoang Ho (Bangiales, Rhodophyta) is a tropical seaweed collected from the west coast of India. Thalli of the blade phase are found growing only during the rainy season between July and September. They grow on rocky intertidal or subtidal substrata or as epiphytes on other seaweeds such as Enteromorpha flexuosa and Chaetomorpha media. The gametophytic thallus is monostromatic and covered with spines at the base. The species is monoecious. Male gametangia are found in patches that are distributed in the upper part of the thallus. Archeospores are found at the thallus margins and give rise to the blade phase after one week of germination even at 30 ∘ C. Zygotospores germinated at 25 ∘ C into conchocelis within three days from the date of their inoculation. Conchospores were released at 30 ∘ C. The young blades grew at 32 ∘ C in the laboratory.

Isethionate in certain red algae

Isethionic acid (2-hydroxyethanesulfonic acid) was isolated as salts from a methanolic extract ofHypnea musciformis collected in the Indian Ocean and identified by comparison (nuclear magnetic resonance, infrared and mass spectrometry) with an authentic sample. The compound has not previously been reported from plants. Investigations of 13 other species of red algae showed that only some samples of species of the families Gigartinaceae, Hypnaceae and Solieriaceae (all of order Gigartinales) contained isethionates.

Process development for the production of bioethanol from waste algal biomass of Gracilaria verrucosa

The algal biomass of different species of Gracilaria were collected from coasts of Orissa and Tamil Nadu, India and characterized biochemically. Among various species, G. verrucosa was found to be better in terms of total carbohydrate content (56.65%) and hence selected for further studies. The agar was extracted from algal biomass and the residual pulp was enzymatically hydrolyzed. The optimization of algal pulp hydrolysis for various parameters revealed a maximum sugar release of 75.8mg/ml with 63% saccharification yield. The fermentation of enzymatic hydrolysate of algal pulp was optimized and 8% (v/v) inoculum size, 12h inoculum age, pH 5.0 were found to be optimum parameters for maximum ethanol concentration (27.2g/L) after 12h. The process of enzymatic hydrolysis and fermentation were successfully scaled up to 2L bioreactor scale.

Production of bioactive hydrolysate using protease, β-glucosidase and α-amylase of Bacillus spp. isolated from kinema

The aim of this study was the production of soybean bioactive hydrolysate using Bacillus spp. isolated from kinema. Totally 251 bacteria isolated from kinema samples, collected at different time period were screened for protease, β-glucosidase and α-amylase activities and further identified by ARDRA based grouping followed by analysis of 16S rRNA gene sequence similarity. The results showed that Bacillus subtilis, Bacillus amyloliquefaciens and Bacillus licheniformis were the major Bacillus species. Twelve fermentative strains belonging to these groups and having high protease, α-amylase and β-glucosidase activity were used for solid state fermentation. The best strains for soybean fermentation that result in production of protein hydrolysates rich in polyphenols that have higher bioactivity were B. subtilis KN12C, B. amyloliquefaciens KN2G and B. licheniformis KN13C. Potential isolates can be applied for the production of soybean hydrolysates and can also find application in production of value added products from by-products of soybean processing industries.

A Critical Survey of Seaweed Diversity of Chilika Lake, India

During the last seventy years several studies have been undertaken on different aspects of marine algae from different parts of the Indian coast. The country has a vast coastline of more than 7,000 km, which harbours a large diversity of marine algal species. So far nearly seven hundred seventy species of marine algae have been reported from different parts of the Indian coast, which includes 184 species of Chlorophyceae, 166 species of Phaeophyceae and 420 species of Rhodophyceae (Sahoo et al. 2001). Although systematic studies on marine algal distribution and diversity are known from different coastal provinces of India, not much published information is available about the marine algal flora of Orissa. The state has a coastline of 460 km covering mostly sandy beaches. Sahoo (1989); Sahoo and Vijayraghvan (1986) reported occurrence of Centroceras clavulatum, Chaetomorpha antennina and Herposiphonia tenella from Gopalpur coast of Orissa. Reports of occurrence of some marine algal species have also been reported from Chilika, a brackish water lake in Orissa. Biswas (1932) in his monumental work reported nine different species of seaweeds from different parts of the lake. Parija and Parija (1947) studied the succession of some algae on a rocky island of the lake. Sahu and Adhikary (1999) reported only six marine algal species from some parts of the lake. Out of all these studies only Biswas gave a detailed authentic monograph on algal flora. But since Biswas’s study in 1932, the lake had undergone several ecological changes due to closing of the lake mouth to the sea thus blocking the entry of saline water to the lake. Besides, large-scale aquacultural activities have gone up in the lake during last several years. Eutrification has also caused several problems to the lake along with siltation. All these activities over the years have not only changed the ecological characters of the lake but also its floristic composition. Thus, the present study is an important step to re-evaluate the seaweeds diversity of the lake.