Biomedical subjects

C Crecchio

Publications and source records attributed to C Crecchio.

4 recordsLinked to original sources

PubMed2007

Molecular and functional characterization of Lactobacillus sanfranciscensis strains isolated from sourdoughs.

Fifty isolates of Lactobacillus sanfranciscensis from Italian sourdoughs were identified and typed by a polyphasic approach which included genotypic and phenotypic criteria. Genotypic diversity was characterized by Ribosomal Intergenic Spacer Analysis (RISA) of PCR amplified 16S-23S rDNA spacer region, denaturing gradient gel electrophoresis (DGGE) of PCR amplified rpoB (beta subunit of RNA polymerase) gene, and rep-PCR (PCR amplification of repetitive bacterial DNA elements) analyses. The RISA analysis produced a unique electrophoretical profile of four bands (ranging from 300 to 600 bp) for all L. sanfranciscensis isolates. The DGGE analysis of rpoB gene allowed the subdivision of isolates in four clusters. The resolution found by using rep-PCR with primers BOXA1R and REP1R-I/REP2-I allowed the widening of the level of isolates heterogeneity. Phenotypic diversity was evaluated by Biolog System and characterization of several technological traits (e.g., acidification kinetics, proteinase and peptidase activities). L. sanfranciscensis isolates used a large varieties of carbon sources such as dextrin, D-fructose, L-fucose, alpha-D-glucose, maltose, palatinose, L-rhanmose, L- and D,L-lactic acids and L-methionine. The acidification activity and related quotient of fermentation, and the peptidase (PepN, PepV, PepT, PepI, PepX, PepQ and PepR) activities markedly varied among strains. The same was found concerning the capacity to liberate amino acids during sourdough fermentation. This study could be considered as an example of a computerized analysis of the genotypic and phenotypic traits to reliably and rapidly differentiate sourdough isolates. Although some L. sanfranciscensis isolates combined several technological traits, the association of more selected strains seemed to be a requisite to get optimal sourdough characteristics.

Bread↗

PubMed1999

Fractionation of sugar beet pulp into pectin, cellulose, and arabinose by arabinases combined with ultrafiltration.

Incubation of beet pulp with two arabinases (alpha-L-arabinofuranosidase and endo-arabinase), used singularly or in combination at different units of activity per gram of beet pulp, caused the hydrolysis of arabinan, which produced a hydrolyzate consisting mainly of arabinose. Pectin and a residue enriched with cellulose were subsequently separated from the incubation mixture. The best enzymatic hydrolysis results were obtained when 100 U/g of beet pulp of each enzyme worked synergistically with yields of 100% arabinose and 91.7% pectin. These yields were higher than those obtained with traditional chemical hydrolysis. The pectin fraction showed a low content of neutral sugar content and the cellulose residue contained only a small amount of pentoses. Semicontinuous hydrolysis with enzyme recycling in an ultrafiltration unit was also carried out to separate arabinose, pectin, and cellulose from beet pulp in 7 cycles of hydrolysis followed by ultrafiltration. The yields of separation were similar to those obtained in batch experiments, with an enzyme consumption reduced by 3.5 times and some significant advantages over batch processes.

Arabinose↗

PubMed1992

Apo C-II deficiency type Bari.

We formerly studied an Italian family with apo C-II deficiency. Two probands were homozygous for the defect (unmeasurable circulating apolipoprotein C-II and absence of C-II bands on immunoelectrophoresis). We documented the synthesis of the protein at the intestinal level in the probands with immunohistological techniques. With the purpose of investigating the molecular basis of the defect, Southern analysis, polymerase chain reaction (PCR) amplification and sequence analysis were carried out on one of the two cases. We identified a point mutation C to G transversion in the third exon of the gene causing a premature stop codon. Our hypothesis is that the truncated protein of 36 aa., instead of 79 aa., lacks its functional domain. This causes inefficiency in the activation of lipoprotein lipase (LPL) and the instability of the circulating molecule, which could have an higher catabolic rate compared to a normal protein. The faster disappearance from the circulating compartment make it unmeasurable. The mutation destroys a Rsa I site, present in the normal gene sequence. We suggest the use of this site for a rapid Restriction Fragment Length Polymorphism (RFLP) on PCR amplification products to screen this defect in the Italian population.

Apolipoprotein C-II↗

PubMed1990

Identification of the mutation responsible for a case of plasmatic apolipoprotein CII deficiency (Apo CII-Bari).

We studied a case of familial Apolipoprotein CII deficiency. By Southern hybridization, amplification and sequence analysis, the genetic defect was identified. It consists in a point mutation C- greater than G in the third exon of the gene causing a premature stop codon. Truncated at the aa. 36 of the mature form, the protein loses its functional domains, becomes inefficient and cannot be detected in the plasma, because of its high instability. The mutation destroys an RsaI site, present in the normal gene sequence. This point mutation is useful in the diagnosis of this Apolipoprotein CII deficiency.

Amino Acid Sequence↗