Ma Alim

Molecular characterization of a blood-induced serine carboxypeptidase from the ixodid tick Haemaphysalis longicornis.

Ticks feed exclusively on blood to obtain their nutrients, but the gene products that mediate digestion processes in ticks remain unknown. We report the molecular characterization and possible function of a serine carboxypeptidase (HlSCP1) identified in the midgut of the hard tick Haemaphysalis longicornis. HlSCP1 consists of 473 amino acids with a peptidase S10 family domain and shows structural similarity with serine carboxypeptidases reported from other arthropods, yeasts, plants and mammals. Endogenous HlSCP1 is strongly expressed in the midgut and is supposed to localize at lysosomal vacuoles and on the surface of epithelial cells. Endogenous HlSCP1, identified as a 53 kDa protein with pI value of 7.5, was detected in the membrane/organelle fraction isolated from the midgut, and its expression was upregulated during the course of blood‐feeding. Enzymatic functional assays revealed that a recombinant HlSCP1 (rHlSCP1) expressed in yeast efficiently hydrolyzed the synthetic substrates specific for cathepsin A and thiol protease over a broad range of pH and temperature values. Furthermore, rHlSCP1 was shown to cleave hemoglobin, a major component of the blood‐meal. Our results suggest that HlSCP1 may play a vital role in the digestion of the hosts blood‐meal.

Evaluation of Quality of Chapaties Enriched with Jackfruit Seed Flour and Bengal Gram Flour

Jackfruit seeds and bengal gram are rich of nutrients as protein, crude fibre, minerals etc. To improve the quality of chapati, jackfruit seed flour and bengal gram flour were used along with wholemeal wheat flour (atta). The aims of this study were to enrich the quality of chapaties and to check the shelf life of chapaties in ambient and refrigerated condition (6 0 C). Four types ( Rc, R1, R2, R3) of chapaties were prepared adding 100% atta in control; 5, 15, 25 percent white and 10, 15, 20 percent brown jackfruit seed flour with 5, 15, 10 percent bengal gram flour respectively. The spread ratio of R3 (46.25) was more than others. Inspite of higher spread ratio of R3 the highest energy (324.73 kcal/100g) containing chapati was R1 type because of its composition. The samples were packed in high density polyethylene and stored at the refrigerated and ambient temperature. The shelf life of chapaties was obtained 3 to 4 days at ambient and 30 days at refrigerated temperature. The sensory attributes of fresh chapaties were also evaluated and found the highest acceptability of R1 sample. This study concluded that the best sample was R1 which had higher energy level and consumer acceptability.

Trematode infections in farm animals and their vector snails in Saint Martin’s Island, the southeastern offshore area of Bangladesh in the Bay of Bengal

The prevalence of snail-borne trematode (SBT) infections in farm animals on the offshore Saint (St.) Martin’s Island of Bangladesh were 68.9% for cattle, 76.7% for buffaloes, 56.3% for goats, respectively. Examination of fecal samples showed that paramphistomes infection was the most common at 50.5% followed by schistosomes at 23.7% and Fasciola at 2.3%. Fasciola infection was found in cattle (1.9%) and buffaloes (16.7%) but not in goats. Schistosome infection in cattle, buffaloes and goats were 31.1, 6.7 and 17.5%, respectively. Prevalence of SBTs was higher in older animals. Thiara tuberculata (Melanoides tuberculata) were found to serve as vector for paramphistomes and Indoplanorbis exustus for schistosomes and paramphistomes, respectively. Our results suggest that SBT and their vector snails are highly endemic on St. Martin’s Island of Bangladesh, and proper attention is needed to control these infections.