The study was conducted to evaluate physico-chemical properties of digested rotten potato (Solanum tuberosum) used as a production medium of spirulina in sixteen days after twenty six days digestion. Three exclusive concentrations such as 20%, 40% and 60% of DRP (digested rotten potato) were used. Spirulina changed into inoculated in supernatant DRP for a period of 14 days. Light intensity (lux/m 2 /s) was varied from 2725 ± 30, 2720 ± 32 and 2730 ± 34, respectively on first day to 2740 ± 30, 2780 ± 27 and 2694 ± 30, respectively on the last day in 20%, 40% and 60% DRPM. The pH values were 9.78 ± 0.07 to 9.95 ± 0.7 on 12 th day in supernatant of 20% DRPM after which it turned into reduced to 9.77 ± 0 on ultimate day of experiment. Its change was observed 9.82 ± 0 to 9.90 ± 0 on 10 th day of experiment of 40% DRPM. The electric conductivity was from 11.22 ± 0.10 to 14.74 ± 0.99, 11.54 ± 0.27 to 14.74 ± 0.99 and 11.23 ± 0.31 to 11.12 ± 0.47 on the 20%, 40% 60% DRPM, respectively. The salinity was 8.10 ± 0.70 in the 20% DRPM. The salinity was 5.17 ± 0 to 6.06 ± 0.26, 6.26 ± 0.17 to 7.60 ± 0.56, whilst spirulina cultured in supernatant of 60 % and 40% DRPM, respectively. The temperature and DO were also fluctuated with variation of DRPM concentration that affects the production of spirulina. The physico-chemical properties of 60 % DRPM was more suitable for spirulina culture.

The study was conducted to evaluate the culture and growth performance of spirulina (Spirulina platensis) in supernatant of three different amounts of digested rotten potato (DRP), and Kosaric medium (KM) as control in 16 days after 26 days digestion. Three different concentrations such as 20, 40 and 60% of DRP were used. Spirulina was inoculated in supernatant DRP along with 9.0 g/L NaHCO 3 and micronutrients, and KM for a period of 14 days. The cell weight of spirulina was attained a maximum of 12.42 ± 0.21 mg/L in KM followed by 8.352 ± 0.21, 6.256 ± 2.34 and 9.505 ± 0.43 mg/L in supernatant of 40, 20 and 60% DRP, respectively on the 10 th day of culture. Similar trend was also observed in the cases of optical density, chlorophyll a, total biomass, specific growth rates. Cell weight of spirulina grown in the media were highly significant (p<0.01) and correlated with the chlorophyll a content and total biomass. The growth performance of spirulina grown in supernatant of 60% DRP was significantly higher than that of spirulina grown in supernatant of 20 and 40% DRP. Therefore, mass culture of spirulina may be done in supernatant of 60% DRP.

Pathogenic microorganisms have been so far reported to contaminate a wide range of foods triggering food borne infections or intoxications including the enteric complications, abdominal pain, fever, bloodstream infection etc. The current study was attempted to observe the microbiological quality of some popular foods collected from different places of Dhaka city, Bangladesh. Conventional cultural, microscopic and biochemical tests were followed for the detection and enumeration of bacterial isolates associated with these food samples. The investigation encompassed detection of total viable bacterial count (TVBC) and presumptive identification of other pathogenic bacteria from these samples. Higher counts of TVBC, coliform, Staphylococcus spp. and fungal load were recorded as 1.46×107 CFU/g (yogurt 1), 4.5×106 CFU/g (yogurt 1), 5.6×105 CFU/g (raw meat) and 2.9×103 CFU/g (sea fish), respectively. Fecal coliform was detected only in one out of ten samples. On the contrary Salmonella spp., Vibrio spp., Shigella spp. and Pseudomonas spp. were completely absent. The antibiogram study showed that all the isolates were sensitive against Kanamycin and Azithromycin. Better sensitivity was also observed against Gentamycin and Ciprofloxacin. Varying degree of antibiotic resistance was also detected against Cefixime, Amikacin and Neomycin. Our study emphasizes the need for continuous monitoring of the various categories of food samples for the safety of public health.

The study was conducted to investigate the productivity and profitability of broiler on L-methionine supplemented diet. A total of 160 day-old broiler chicks (Cobb 500) was randomly distributed to four dietary supplements, D0 (Control), D1 (0.30 % L-Met), D2 (0.35 % L- Met) and D3 (0.40 % L- Met). Each treatment was replicated five times with 8 birds per cage. The chicks were reared in the battery cages while they were fed with broiler starter diet (crumble) until Day14 of age. The birds with fed with L-Met supplemented diets starting from Day15 until Day35 of age All the diets were iso-caloric and iso-nitrogenous.. Results revealed that the L-Met supplementations were in favor of higher live weight (LW) and better (p<0.05) feed conversion ratio without affecting the feed intake (FI). The D3 diet resulted higher (p<0.01) LW in the birds than all others on Day35 of age. The livability (%) was unaffected (p>0.05) by the dietary supplements. No significant (p>0.05) difference was observed in the relative weights of visceral organs (small intestine, proventriculus, gizzard, liver and heart) except for the spleen. Relatively increased (p<0.05) spleen weight (%) was observed in the D3 diet. The breast weight (%) was increased marginally (p<0.07) in the D3 group, while the other carcass parts; breast weight, thigh weight, wing weight, shank weight, drumstick weight, neck weight, and abdominal fat content were found to be similar (p>0.05) in the dietary groups. Higher profit (p<0.01) and lower production cost (p<0.05) were observed in the D3 group than that of the others. It can be inferred that 0.40% L-Met supplementation in the broiler diet is better for growth performance and profitability. Bang. J. Livs. Res. Vol. 27 (1&2), 2020: P. 1-14