Carotenoids are isoprenoid pigments used by pharmaceutical, cosmetic, food and feed industry as antioxidants and colorants. Although traditional sources of carotenoids are fruits, vegetables and chemical synthesis, prospecting for alternative sinks of common and/or unusual carotenoids is important for the development of natural carotenoid industry. In this work, 30 pigmented bacterial strains from Fildes Peninsula in King George Island, Antarctica, were isolated and identified by 16S rRNA gene sequencing and classified in three phyla, Bacteroidetes, Firmicutes and Actinobacteria. After cells extraction, ten different carotenoids were identified based on the chromatographic and spectroscopic characteristic obtained by HPLC-PDA and HPLC-PDA-APCI-MS analyses. Strains assigned to Bacteroidetes affiliated to Flavobacterium, Chryseobacterium and Zobellia genera, presented a pigment profile composed of zeaxanthin, β-cryptoxanthin and β-carotene. Firmicutes strains of Planococcus genus produced a C50 carotenoid, identified as C.p. 450 glucoside. Actinobacteria isolates were mainly assigned to Arthrobacter genus, and few to Salinibacterium and Cryobacterium genera. Arthrobacter strains produced C50 carotenoids such as decaprenoxanthin and its glucosylated derivatives, as well as some C40 carotenoids such as lycopene which is used as synthesis precursors of the C50 carotenoids. Salinibacterium and Cryobacterium genera produced C.p. 450 free form and its glucosylated derivatives. Although most isolates produce carotenoids similar in diversity and quantity than those already reported in the literature, novel sources for C50 carotenoids results from this work. According to their carotenoid content, all isolates could be promising candidates for carotenoids production.

The enzymatic starch hydrolysis and bioethanol production from a variety of sweet potato developed for bioenergy purposes (K 9807.1) on the basis of its high starch yields, was studied. Drying at 55°C and 95°C of sweet potato neither affected the sugar content nor the starch enzymatic hydrolysis efficiency. Simultaneous saccharification and ethanol fermentations for dry matter ratio of sweet potato to water from 1:8 to 1:2 (w/v) were studied. Fresh sweet potato and dried at 55°C (flour) were assayed. At ratios of 1:8, similar results for fresh sweet potato and flour in terms of ethanol concentration (38–45 g/L), fermentation time (16 h) and sugar conversion (~ 100%) were found. At higher dry matter content, faster full conversion were observed using flour. A higher ratio than that for fresh sweet potato (1:2.2) did not improve the final ethanol concentration (100 g/L) and yields. High ethanol yields were found for VHG (very high gravity) conditions. The sweet potato used is an attractive raw matter for fuel ethanol, since up to 4800 L ethanol per hectare can be obtained.