Sweetpotato [sweet potato; Ipomoea batatas (L.) Lam.] is the seventh most valued food crop of the world. It has an inherent ability to grow under diverse agro-ecological and microclimatic zones ranging from tropical and subtropical zones to temperate areas with its tuberous roots enriched with the secondary metabolites of immense nutritional value. Among these, carotenoids are the most conspicuous one for having their use in nutritional, pharmaceutical, food, feed, aquaculture, and cosmetic industries. In food industries, carotenoids are used as food additives being antioxidants with attractive colors. Despite the immense economic importance, sweetpotato has received lesser attention in terms of its breeding with improved varieties. The conventional method of breeding by crossing has not been much successful due to the complexity of genome sterility and cross-incompatibility. Hence, the modern molecular breeding approaches, e.g. genetic, genomic, and metabolic (pathway) engineering, have been applied to this crop by some of researchers in Japan, Korea, and China to generate various cultivars with improved quantities and qualities of carotenoids. This has also opened a new gate for molecular breeders to engineer new sweetpotato cultivars enriched with carotenoids under current global scenario of dramatically rising climatic changes where novel food resources are bitterly needed, especially under alarmingly growing world population, the majority of which suffers from malnutrition.

Endopolygalacturonase (EndoPGase) is one of the crucial pectinases belonging to the class of carbohydrase. The catalytic action of EndoPGase captivate the attention for production of this extremely valuable catalyst of industrial sector. The main focus was to ascertain a potential bacterial candidate for endoPGase production. The isolated bacterial strain was further identified by 16S rDNA gene sequencing. A genomic library was constructed by using Lambda ZAP II vector system to investigate the pectinolytic potential of the expressed genes. The parameters for enzyme biosynthesis were optimized by single as well as multiple factor approach at a time. The results of our investigation led to the identification of a potent strain of Bacillus subtilis NR2. The strain was found active for pectic enzyme activity under shaking- flask fermentation at pH 5.0 and 50 °C temperature of incubation. Among all monomeric and polymeric substrates, citrus pectin followed by wheat bran was considered the best enzyme inducers at 1 % concentration. Moreover, an increasing trend in enzyme activity was observed with the increasing inducer concentration. The combined effect of three variables (pH, substrates, and substrate concentration) was explored by response surface methodology involving Box Benken Design (BBD). The study concluded that the soil isolated B. subtilis can be utilized for commercial scale pectinase enzyme production.