Shirlei Scramin

Antifungal compound produced by the cassava endophyte Bacillus pumilus MAIIIM4a

In the search for new organisms and new secondary metabolites, a study was conducted to evaluate the diversity of endophytic bacteria from ethnovarieties of cassava cultivated by Brazilian Amazon Indian tribes and also to study the secondary metabolites produced by a Bacillus pumilus strain. Sixty seven cassava endophytic bacteria were subjected to 16S rRNA sequencing and FAME analysis. The bacterial profile revealed that 25% of all endophytic isolates belonged to the genus Bacillus. The isolate B. pumilus MAIIIM4a showed a strong inhibitory activity against the fungi Rhizoctonia solani, Pythium aphanidermatum and Sclerotium rolfsii. Secondary metabolites of this strain were extracted using hexane, dichloromethane and ethyl acetate. Extracts were subjected to bioautography and LC/MS analysis, which allowed the identification of pumilacidin, an antifungal compound produced by B. pumilus MAIIIM4a. The bacterial endophytic localization was confirmed by cassava cell tissue examination using scanning electron microscopy.

Optimization of lipids production by Cryptococcus laurentii 11 using cheese whey with molasses

This study aimed the optimization of culture condition and composition for production of Cryptococcus laurentii 11 biomass and lipids in cheese whey medium supplemented with sugarcane molasses. The optimization of pH, fermentation time, and molasses concentration according to a full factorial statistical experimental design was followed by a Plackett-Burman experimental design, which was used to determine whether the supplementation of the culture medium by yeast extract and inorganic salts could provide a further enhancement of lipids production. The following conditions and composition of the culture medium were found to optimize biomass and lipids production: 360 h fermentation, 6.5 pH and supplementation of (g L−1): 50 molasses, 0.5 yeast extract, 4 KH2PO4, 1 Na2HPO4, 0.75 MgSO4·7H2O and 0.002 ZnSO4·H2O. Additional supplementation with inorganic salts and yeast extract was essential to optimize the production, in terms of product concentration and productivity, of neutral lipids by C. laurentii 11. Under this optimized condition, the production of total lipids increased by 133% in relation to control experiment (from 1.27 to 2.96 g L−1). The total lipids indicated a predominant (86%) presence of neutral lipids with high content of 16- and 18-carbon-chain saturated and monosaturated fatty acids. This class of lipids is considered especially suitable for the production of biodiesel.

Essential Oil of Elyonurus muticus (Sprengel) O.Kuntze (Gramineae)

Abstract Twelve compounds were identified by GC/MS in the essential oil of Elyonurus muticus leaves, native in the Brazilian Pantanal. Spathulenol (18.6%), β-caryophyllene (17.9%) and camphene (11.5%) were the major components found in the oil.

Volatile constituents of Hyptis crenata Pohl (Labiatae) native in Brazilian Pantanal.

Abstract Fifteen compounds were identified in the essential oil of Hyptis crenata Pohl, which was analyzed by GC/MS. The main oil components were α-pinene (15.5%), β-pinene (10.5%), camphor (17.3%), and β-caryophyllene (10.7%). The volatile concetrate isolated from the distillation water contained 1,8-cineole (11.9%), camphor (37.3%) and β-caryophyllene (14.7%).