Microbiological processes were used for chitin and chitosan productions by Cunninghamella elegans (UCP 542) grown in a new economic culture medium. The assay was carried out to evaluate the growth of C. elegans using yam bean (Pachyrhizus erosus L. Urban) medium, in different times of growth (24, 48, 72 and 96 hrs), incubated at 28ºC in an orbital shaker at 150 rpm. The lyophilized biomass was determined by gravimetry. The polysaccharides were extracted by alkali-acid treatment, and characterized by infrared spectroscopy, titration and viscosity. C. elegans grown in the yam bean medium and produced higher yields of biomass (24.3 g/ mL) in 96 hrs. The high level was chitosan (66 mg/g), and chitin (440 mg/g) were produced at 48 and 72 hrs of growth, respectively. The polysaccharides showed degree of deacetilation and viscosimetric molecular weight as: 6.2% and 3.25 x10(4) g/mol for chitin, and 85% and 2.72 x 10(4) g/mol for chitosan, respectively. The results obtained suggest high biotechnological potential of yam bean as an economic source to produce chitin and chitosan by C. elegans. In addition, the new medium using yam bean for production of the chitin and chitosan may be used for many purposes to reduce the cost price of fermentation processes.

This paper is a translation from IUPAC nomenclature document by K. Danzer and L. A. Currie (Pure Appl. Chem., 1998, 70(4), 993-1014). Its goal is to establish an uniform and meaningful approach to terminology (in Portuguese), notation, and formulation for calibation in analytical chemistry. In this first part, general fundamentals of calibration are presented, namely for both relationships of qualitative and quantitative variables (relations between variables characterizing certain types analytes of the measured function on the other hand and between variables characterizing the amount or concentration of the chemical species and the intensities of the measured signals, on the other hand). On this basis, the fundamentals of the common single component calibration (Univariate Calibration) which models the relationship y = f(x) between the signal intensities y and the amounts or concentrations x of the analyte under given conditions are represented. Additional papers will be prepared dealing with extensive relationships between several intensities and analyte contents, namely with multivariate calibrations and with optimization and experimental design.

Um planejamento fatorial de dois níveis foi empregado para analisar a influência da agitação, do tempo de contato, da quantidade de alga e do tipo de pré-tratamento sobre a remoção de metais pesados por algas Arribadas, num sistema em batelada contendo uma solução sintética simulando um efluente típico de fabricação de baterias. Amostras de 4 g de algas secas, moídas e peneiradas removeram 99% do chumbo de amostras de 100 mL do efluente sintético. Os percentuais máximos de remoção de zinco e ferro foram 37% e 80%, respectivamente. Como as algas arribadas são baratas, abundantes e de ocorrência natural, a remoção de chumbo através deste método pode ser vantajosa para aplicação industrial em larga escala.

A two-level factorial design was employed to analyze the influence of agitation, contact time, amount of algae and type of pretreatment on heavy metal removal by Arribadas algae, in a batch system consisting of a synthetic solution simulating a typical effluent from battery manufacturing processes. Dried, ground and sieved 4 g algae samples were able to remove 99 % lead from 100 mL samples of synthetic effluent. Maximum removals for zinc and iron were 37 % and 80 %, respectively. Lead removal using this method is potentially useful for large-scale industrial applications, because Arribadas algae are cheap, abundant, naturally occurring waste materials.

This review presents the evolution of simultaneous multicomponent analysis by absorption spectrophotometry in the ultraviolet and visual regions in terms of some qualitative and quantitative analysis techniques, otimization methods, as well as applications and modern trends.