Pioneer access of the foam nest bacterial community of Leptodactylidae frogs and its biotechnological potential.

Many anuran amphibians deposit their eggs in foam nests, biostructures that help protect the eggs and tadpoles from predators. Currently, there are no other identification and description studies of the cultivable microbiota role in the nests of the Leptodactylid frogs such as Physalaemus cuvieri, Leptodactylus vastus and Adenomera hylaedactyla. This study aimed to isolate and identify the culturable bacteria from these three anuran species' nests, as well as to prospect enzymes produced by this microbiota. Foam nests samples and environmental samples were diluted and viable cell count was determined. Bacterial morphotypes from foam nest samples were isolated through spread plate technique. Isolates' DNAs were extracted followed by rRNA 16S gene amplification and Sanger sequencing. To evaluate their enzymatic potential, the isolates were cultured in ATGE medium supplemented with starch (0.1% w/v), gelatin (3% w/v) and skimmed milk (1% w/v), to verify amylase and protease activity. A total of 183 bacterial morphotypes were isolated, comprising 33 bacterial genera. Proteobacteria phylum was the most abundant in all the three nests (79%). The genera Pseudomonas and Aeromonas were the most abundant taxon in P. cuvieri and L. vastus. In A. Hylaedactyla, were Enterobacter and Bacillus. Regarding enzymatic activities, 130 isolates displayed protease activity and 45 isolates were positive for amylase activity. Our results provide unprecedented information concerning culturable bacterial microbiota of the foam nests of the Leptodactylid frogs, as well as their potential for biomolecules of biotechnological interest.

Sustainable recovery of protein-rich liquor from shrimp farming waste by lactic acid fermentation for application in tilapia feed.

The biotransformation of shrimp head waste into ingredients for Nile tilapia (Oreochromis niloticus) post-larvae (PLs) diet formulations was evaluated herein. A novel consortium of lactic acid bacteria, comprising the strains Lactobacillus futsaii LAB06 and L. plantarum LAB14, selected based on kinetic growth parameters, was applied in the fermentation of shrimp head waste. After 48 h, the highest lactic acid production was 100 g L-1, allowing for maximum recovery of chitin and protein-rich liquor. The liquor was added to commercial powdered fish feed at 15, 30, and 45% (w/w) and offered to Nile tilapia PL during 28 days. The inclusion of 30% provided the best results for Nile tilapia PL survival, weight and length gains, specific growth rate, and biomass, proving that the fermented liquor can be incorporated, leading to economic benefits and contributing to the reduction of environmental pollution caused by the improper disposal of shrimp waste.

Alternative method for quantification of alfa-amylase activity.

A modification of the sensitive agar diffusion method was developed for macro-scale determination of alfa-amylase. The proposed modifications lower costs with the utilisation of starch as substrate and agar as supporting medium. Thus, a standard curve was built using alfa-amylase solution from Aspergillus oryzae, with concentrations ranging from 2.4 to 7,500 U.mL-1. Clear radial diffusion zones were measured after 4 hours of incubation at 20 A degrees C. A linear relationship between the logarithm of enzyme activities and the area of clear zones was obtained. The method was validated by testing alpha-amylase from barley at the concentrations of 2.4; 60; 300 and 1,500 U.mL-1. The proposed method turned out to be simpler, faster, less expensive and able to determine on a macro-scale alpha-amylase over a wide range (2.4 to 7,500 U.mL-1) in scientific investigation as well as in teaching laboratory activities.

New approach for petroleum hydrocarbon degradation using bacterial spores entrapped in chitosan beads.

Spores of Bacillus subtilis LAMI008 were entrapped in 3-mm chitosan beads and cross-linked with 0.3% glutaraldehyde for n-hexadecane biodegradation and biosurfactant recovery. When exposed to nutrients, the spores generated vegetative cells without morphological alterations as revealed by atomic force microscopy. The entrapped cells degraded almost 100% of 1% of n-hexadecane in medium supplemented with 1% glucose and produce biosurfactant within 48 h, as well as free cells. The number of viable cells inside the beads was maintained throughout the n-hexadecane degradation process and the released biosurfactant was not used as a carbon source. Entrapment of bacterial spores in chitosan beads overcomes problems with stability, storage, and long term cell viability encountered with vegetative cells. This approach can potentially be utilized for biodegradation of complex compounds by entrapping spores of different species of bacteria.

Comparisons of referral criteria for public screening of blood cholesterol levels.

Total and high-density lipoprotein (HDL) cholesterol levels of 2,387 adults were screened at a worksite and a bloodbank. Hypothetical referral decisions were made according to three sets of guidelines: the 1984 National Institutes of Health Consensus Conference guidelines (NIHCC), a single referral cutpoint of 5.2 millimoles per liter (mmol per L), and the current National Cholesterol Education Program (NCEP) guidelines for screening in physicians' office. Under the NIHCC guidelines, 31 percent of the participants would have been referred to their physicians, 32 percent under the NCEP guidelines, and 56 percent would have been referred had the 5.2 mmol per L cutpoint been used. Twenty-four percent of the participants would have been referred under both the NIHCC and NCEP guidelines; 7 percent would have been referred under the NIHCC guidelines, but not the NCEP's. Eight percent would have been referred under the NCEP guidelines, but not the NIHCC's. Those who would have been referred were older, and more likely to be male and to have low levels of HDL cholesterol than the 7 percent who would have been referred under NIHCC guidelines only. All of the 8 percent had coronary heart disease, or two or more other coronary risk factors, whereas none of the 7 percent did. If low HDL had been used as a risk factor under NCEP guidelines, the number of persons referred would have increased slightly (to 34 percent) and low HDL levels would have become one of the most prevalent risk factors. The researchers concluded that public cholesterol screening programs should use the NCEP guidelines (with or without HDL), rather than the NIHCC guidelines, or a single 5.2 mmol per L cutpoint.

Should physicians perform their own quality assurance audits?

Quality assurance is required of all hospital outpatient clinics although there is little evidence documenting its value. The purposes of this study were to assess the impact of quality assurance audits on physicians' ordering behavior and to learn whether doctors who actually performed audits behaved differently from physicians who passively received audit results. Baseline influenza vaccination and screening mammography ordering rates were established for the authors' residents' clinic in 1985. In 1986, residents were assigned randomly to three groups. Residents in one group audited their own charts for 1985 influenza vaccination ordering; the second group audited its own charts for 1985 screening mammography ordering; and the third group performed no audit but received the other groups' results. Passive receipt of results improved ordering of vaccination from 40% to 59% and ordering of mammography from 8% to 16%. Actual performance of audits improved ordering of mammography from 16% to 26% but did not improve vaccination ordering. These quality assurance audits were effective in improving the performance of selected preventive health measures in a residents' clinic.