Rojan P. John

Micro and macroalgal biomass: A renewable source for bioethanol

Population outburst together with increased motorization has led to an overwhelming increase in the demand for fuel. In the milieu of economical and environmental concern, algae capable of accumulating high starch/cellulose can serve as an excellent alternative to food crops for bioethanol production, a green fuel for sustainable future. Certain species of algae can produce ethanol during dark-anaerobic fermentation and thus serve as a direct source for ethanol production. Of late, oleaginous microalgae generate high starch/cellulose biomass waste after oil extraction, which can be hydrolyzed to generate sugary syrup to be used as substrate for ethanol production. Macroalgae are also harnessed as renewable source of biomass intended for ethanol production. Currently there are very few studies on this issue, and intense research is required in future in this area for efficient utilization of algal biomass and their industrial wastes to produce environmentally friendly fuel bioethanol.

Direct lactic acid fermentation: focus on simultaneous saccharification and lactic acid production.

In the recent decades biotechnological production of lactic acid has gained a prime position in the industries as it is cost effective and eco-friendly. Lactic acid is a versatile chemical having a wide range of applications in food, pharmaceutical, leather and textile industries and as chemical feedstock for so many other chemicals. It also functions as the monomer for the biodegradable plastic. Biotechnological production is advantageous over chemical synthesis in that we can utilize cheap raw materials such as agro-industrial byproducts and can selectively produce the stereo isomers in an economic way. Simultaneous saccharification and fermentation can replace the classical double step fermentation by the saccharification of starchy or cellulosic biomass and conversion to lactic acid concurrently by adding inoculum along with the substrate degrading enzymes. It not only reduces the cost of production by avoiding high energy consuming biomass saccharification, but also provides the higher productivity than the single step conversion by the providing adequate sugar release.

Bio-encapsulation of microbial cells for targeted agricultural delivery

Biofertilizers, namely Rhizobium and biocontrol agents such as Pseudomonas and Trichoderma have been well established in the field of agricultural practices for many decades. Nevertheless, research is still going on in the field of inoculant production to find methods to improve advanced formulation and application in fields. Conventionally used solid and liquid formulations encompass several problems with respect to the low viability of microorganisms during storage and field application. There is also lack of knowledge regarding the best carrier in conventional formulations. Immobilization of microorganisms however improves their shelf-life and field efficacy. In this context, microencapsulation is an advanced technology which has the possibility to overcome the drawbacks of other formulations, results in extended shelf-life, and controlled microbial release from formulations enhancing their application efficacy. This review discusses different microencapsulation technologies including the production strategies and application thereof in agricultural practices.

Biochemical diversity of the bacterial strains and their biopolymer producing capabilities in wastewater sludge

The biochemical characterization of 13 extracellular polymeric substances (EPS) producing bacterial strains were carried out by BIOLOG. The bacterial strains were cultured in sterilized sludge for EPS production. Flocculation and dewatering capabilities of produced EPS (broth, crude slime and capsular) were examined using kaolin suspension combined with calcium (150 mg of Ca(2+)/L of kaolin suspension). BIOLOG revealed that there were 9 Bacillus, 2 Serratia and 2 Yersinia species. Most of these bacterial strains had the capability to utilize wide spectrum of carbon and nitrogen sources. EPS concentration of more than 1g/L was produced by most of the bacterial strains. Concentration of EPS produced by different Bacillus strains was higher than that of Serratia and Yersinia. Broth EPS revealed flocculation activity more than 75% for Bacillus sp.7, Bacillus sp.4 and Bacillus sp.6, respectively. Flocculation activity higher than 75% was attained using very low concentrations of broth EPS (1.12-2.70 mg EPS/g SS).

L(+)-Lactic acid recovery from cassava bagasse based fermented medium using anion exchange resins

As propriedades das resinas de troca ionica, da Amberlite IRA 402, uma resina de troca anionica forte, e da IRA 67, uma resina de troca anionica fraca, foram determinadas para se avaliar a adequabilidade comparativa delas a obtencao de acido latico de bagaco de mandioca fermentado. Dados sobre a capacidade de ligacao e sobre a obtencao provaram que a resina de base fraca na forma de cloreto era a mais adequada para a obtencao de acido latico em solucoes aquosas e meios de fermentacao. Os meios de fermentacao obtidos da sacarificacao e da fermentacao simultâneas de meios baseados hidrolisados de fecula de bagaco de mandioca foram usados para o estudo da obtencao de acido latico usando uma coluna de resina de base fraca. A Amberlite IRA 67 mostrou-se muito mais eficaz do que a Amberlite IRA 402 para a obtencao de acido latico. Como em outros relatorios, devido a presenca de nutrientes e ions que nao lactatos, a capacidade de ligacao foi ligeiramente inferior enquanto se utilizavam meios fermentados em vez de solucoes acidas laticas aquosas.

Biotechnological Potentials of Cassava Bagasse

Crop residues such as cassava bagasse are annually renewable sources of energy. Though they are rich in carbohydrate, their utilization for any direct application is very less due to the low content of protein and poor digestibility. However, the utilization of such agro-industrial residues provides alternative substrate for bioprocesses and will solve the problem of environmental pollution to an extent. Several processes have been developed to utilize cassava bagasse, the fibrous residue of the tropical tuber for the production of value added products such as organic acids, ethanol, aroma, mushroom etc. The chapter focuses on the wide spectrum applications of cassava bagasse in bioprocess technology.

Carbon burial and enhanced soil carbon trapping

Sponsored by the Carbon Capture and Storage Task Committee of the Technical Committee on Hazardous, Toxic, and Radioactive Waste Engineering of the Environmental Council of EWRI.