Central Tuber Crops Research Institute

About: Central Tuber Crops Research Institute is a facility organization based out in Thiruvananthapuram, Kerala, India. It is known for research contribution in the topics: Starch & Fermentation. The organization has 475 authors who have published 587 publications receiving 10285 citations.

Solid State Fermentation for Production of Microbial Cellulases

Abstract: Cellulose, present in renewable lignocellulosic material, is considered to be the most abundant organic substrate on earth for production of hexose and pentose sugars, feedstock for fuel, and for other chemicals. Research on cellulase has progressed very rapidly in the past few decades with an emphasis on enzymatic hydrolysis of cellulose to hexose sugars. The enzymatic hydrolysis of cellulose requires the use of cellulase [1,4-(1,3:1,4)-β-D-glucan glucanohydrolase, EC 3.2.1.4], a multiple enzyme system consisting of endo-1,4,-β-D-glucanases [1,4-β-D-glucanases (CMCase, EC 3.2.1.4)], exo-1,4,-β-D-glucanases [1,4-β-D glucan cellobiohydrolase, FPA, EC 3.2.1.91], and β—glucosidase (cellobiase) (β-D-glucoside glucanohydrolase, EC 3.2.1.21). Major impediments to exploit the commercial potential of cellulases are the economic yield, stability, specificity, and above all, the cost of production. In the last few years, emphasis has been devoted mainly to submerged fermentation and less attention has been given to solid state fermentation (SSF). SSF refers to the process whereby microbial growth and product fermentation occur on the surface of solid materials. This process occurs in the absence of “free” water, where the moisture is absorbed to the solid matrix. The direct applicability of the product, the high product concentration, lower production cost, easy product recovery, and reduced energy requirement make SSF a promising technology for cellulase production. This chapter covers the production of cellulase in SSF using various lignocellulosic substrates, the microorganisms involved, cultural conditions, process parameters (ie, moisture content and water activity, mass transfer processes: aeration and nutrients diffusion, substrate particle size, temperature, pH, surfactants, etc.), bioreactor designs, and the strategies to improve enzyme yield.

Whey Protein Concentrate Fortified Baked Goods from Cassava-Based Composite Flours: Nutritional and Functional Properties

Abstract: Composite flours are extensively used in the bakery industry to develop designer food products, having specific nutritional or functional properties. Though rich in carbohydrate, cassava flour has not been properly exploited for making bakery products, mainly because of its low protein content contributing to poor dough characteristics. Induced malting using amylolytic enzymes and pregelatinization through hydrothermal cooking were tried to modify the textural and functional attributes of cassava flour, which was then blended with various cereal and legume additives as well as rice bran and used for making two baked products such as muffins and biscuits. Whey protein concentrate (WPC) was added to fortify protein in all the formulations. Pseudo-malted cassava flour-based muffins and biscuits had lower starch content (36–44% and 36.5–41.2%, respectively) than similar products from unmalted cassava flour (39–46% and 43.75%, respectively). The crude protein content of the muffins and biscuits from WPC fortified composite mixes ranged from 7.96% to 14.36% and 9.63% to 11.00%, respectively, which was significantly higher than the native cassava flour (1.30%). Besides, the total dietary fiber could be enhanced to the extent of 1.54–3.10% in muffins and 1.70–2.61% in biscuits, through fortification with cereal and/or legume flours or bran sources, which is also considerable when compared to only 0.435% in native cassava flour. In vitro starch digestibility was the lowest for cassava (unmalted)-/rice bran-based muffins (25.02 units) and cassava (unmalted)-/finger millet flour-based biscuits (36.08 units), indicating the potential of these combinations for making therapeutic baked products for obese and diabetic people. Spread ratio and spread factor were the least (9.27 and 60.99, respectively) for the biscuits made with unmalted cassava/finger millet mixes, while use of Termamyl pseudo-malted cassava/finger millet raised the spread ratio to 11.11 and spread factor to 73.09.

Identification and characterization of differentially expressed genes in the resistance reaction in taro infected with Phytophthora colocasiae

Abstract: Leaf blight disease caused by Phytophthora colocasiae represents a major constraint to the growth and yield of taro (Colocasia esculenta L.). Ongoing research on model plant systems has revealed that defense responses are activated via signaling pathways mediated by endogenous signaling molecule such as salicylic acid, jasmonic acid, and ethylene. Activation of plant defenses is associated with changes in the expression of large number of genes. To gain a better understanding of defense responses, virulent race of P. colocasiae was used to inoculate the taro cultivar UL-56 (compatible) and its nearly isogenic line Muktakeshi (incompatible). We have employed suppressive subtractive hybridization (SSH), cDNA libraries, Northern blot analysis, high throughput DNA sequencing, and bioinformatics to identify the defense-related genes in taro induced by P. colocasiae infection. Two putative resistance genes and a transcription factor were identified among the upregulated sequences. The expression of several candidate genes including lipid transfer proteins (LTPs), and other pathogenesis-related genes were evaluated following 8–48 h of appearance of symptom in compatible and incompatible interactions. Results confirmed the higher overall expression of these genes in Muktakeshi (resistant) compared to UL-56 (susceptible). This study constitutes the first attempt to characterize the taro differential transcriptome associated with host–pathogen interactions from different genotypes. All the generated ESTs have been submitted to GenBank for further functional studies.

A species-specific polymerase chain reaction assay for rapid and sensitive detection of Sclerotium rolfsii

Abstract: The failure to adequately identify plant pathogens from culture-based morphological techniques has led to the development of culture-independent molecular approaches. The timely and accurate detection of pathogens is critical in the study of epidemiology and management of plant diseases. A polymerase chain reaction (PCR)-based method was developed for the identification and detection of Sclerotium rolfsii in Amorphophallus paeoniifolius plants. A PCR primer pair specific for S. rolfsii was designed based on the sequence of the internal transcribed spacer region. The designed primer pair SCR-F/SCR-R amplified a 540-bp product from S. rolfsii DNA and did not amplify DNA from A. paeoniifolius or several other fungi pathogenic to A. paeoniifolius. In conventional PCR, the limit of detection of pure fungal gDNA was 6 pg ml−1, which was reduced 2-fold within a plant DNA background. S. rolfsii DNA was detected in inoculated A. paeoniifolius and 12 h after inoculation in symptomless tuber samples. The protocol was assessed for the detection of S. rolfsii in infected soils.

Functional properties of the starchy flour extracted from cassava on fermentation with a mixed culture inoculum

Abstract: The functional properties of the starchy flour extracted from six varieties of cassava subjected to fermentation by a mixed culture inoculum comprised of lactobacilli, streptococci, corynebacteria and yeast cells are examined. Apparent reduction in total and soluble amylose contents is observed. Differential scanning calorimetry of the samples indicated that the enthalpy of gelatinisation was reduced, while the gelatinisation temperature was enhanced. A marked reduction in Brabender viscosity values of starch from fermented tuber was observed, but the X-ray diffraction pattern was unaffected. All these changes were attributed to the presence of fibrous material and consequent reduction of starch in unit volume rather than any change in the starch granule structure.