Study for investigated the optimum photoperiod from blue LED light for the growth of Chlorella vulgaris in culture tank. Photoperiods from blue LED Light (Light/Dark) were set up at 24:0, 16:8 and 12:12 h. The initial number of C. vulgaris cells was 1.6 x 105 ± 0.12 cells mL-1. Culture medium was using commercially available fertilizers. After 17 days of cultivation, the results showed that the 24:0 h photoperiod had better growth of algae than 16:8 and 12:12 h, with maximum number of cells of 1.64 x 107 ± 0.23 cells mL-1 specific growth rate (SGR) was 0.17 ± 0.05, -0.06 ± 0.11 and -0.19 ± 0.1% day-1 with statistically significant differences (P < 0.05) in day 5 of cultivation. The stationary phase continued up to day 3 of cultivation, between the treatment. The optimum temperature for growth ranged from 35.5–38.5°C. The results showed that blue LED lighting at 24:0 h is the optimum photoperiod for cultivation of C. vulgaris. Keywords: Photobioreactor tank, Photoperiod, Blue LED light, Chlorella vulgaris, Growth rate

This study investigates the influence of varying nitrogen-to-phosphorus (N:P) ratios on the growth, nutritional composition, and nutrient removal efficiency of Wolffia globosa under controlled laboratory conditions. Six treatments with N:P ratios of 1:3, 1:2, 1:1, 2:1, 3:1, and a control were evaluated. The findings indicate that a balanced N:P ratio (1:1) promotes optimal growth, resulting in the highest biomass yield and specific growth rate (SGR = 0.120 g/day). In contrast, a nitrogen-rich ratio (3:1) enhanced protein accumulation and phosphorus removal, while the 2:1 ratio favored nitrogen uptake. These results reflect underlying physiological responses, including nitrogen assimilation and phosphorus uptake mechanisms regulated by nutrient balance. A trade-off was observed between biomass production and phosphorus removal efficiency, suggesting that different N:P ratios may be suited to specific application goals. This study contributes to a more comprehensive understanding of how macronutrient balance affects growth and metabolism in W. globosa and offers practical implications for optimizing its use as both a sustainable protein source and a biological agent for nutrient remediation in wastewater treatment systems.

Background: Avian pathogenic Escherichia coli (APEC) are significant bacterial pathogens that cause economic losses in the poultry industry and can pose a potential foodborne zoonotic risk. Herein, we examined APEC distribution and antimicrobial resistance in E. coli isolated from slaughtered broiler chickens in northern Thailand. Methods: PCR was used to classify APEC as either virulent or avirulent on 108 stored E. coli strains, as well as to perform Clermont phylotyping. Antimicrobial susceptibility to ciprofloxacin, cefotaxime, ceftazidime, imipenem, and colistin was examined. Results: Of the 108 E. coli strains, 101 (93.5%) isolates were APEC, and the remaining isolates were non-APEC. Among the APEC isolates, 58.4% were classified as virulent APEC; these isolates showed a statistically significant association with phylogroups F and C and (n = 54, 56.8%) more frequently exhibited a ciprofloxacin-resistant phenotype than avirulent APEC (n = 35, 36.8%). Among the ten APEC virulence genes, hlyF, iroC, iroN, iutA, O78, and ompT were significantly associated with virulent APEC. Conclusions: This study reveals a high prevalence of virulent APEC with fluoroquinolone resistance in slaughtered broiler chickens. Almost all virulent APEC strains belong to phylogroups F and C. The prediction of virulent APEC using hlyF, iroC, iroN, iutA, O78, and ompT may be useful.

This study demonstrates an effective cultivation protocol for Wolffia globosa through a bio-inspired approach. Light parameters from the plant's natural, shaded habitats (PPFD ~44 µmol m⁻² s⁻¹) were first characterized to calibrate a laboratory LED system. The experiment revealed that a one-time nutrient supplementation at initiation was the critical factor for sustained growth. While all treatments were exposed to the same light regimen, the unenriched groups (C, T1, T2, and T5) experienced a "bloom-and-bust" cycle, with growth ceasing after day 9. In contrast, treatments supplemented with N-P-K fertilizer (T3 and T4) maintained a positive specific growth rate (SGR) throughout the 15-day experimental period (max SGR 0.11–0.23 day⁻¹). This finding provides a practical proof-of-concept demonstrating that a low-energy, bio-inspired lighting strategy is sufficient for cultivating W. globosa in closed systems, provided the plant's fundamental nutrient requirements are satisfied. This study presents a sustainable, energy-efficient alternative to conventional high-intensity lighting methods for aquatic plant production.

This study aimed to investigate the effects of glucose and lime concentrations in the culture medium on growth of Chlorella ellipsoidea and water quality during the cultivation. The experiment included seven treatment groups: a control group (0.5 g/L glucose, 0.4 g/L lime) and groups with reduced glucose concentrations (0.4, 0.3, 0.2, 0.1 g/L) and lime concentrations (0.2, 0.1 g/L). Cultivation lasted for 15 days, with algal growth assessed by cell counting, and water quality parameters such as alkalinity, pH, and ammonia levels analyzed daily. The results showed that the G20 (0.1 g/L glucose) group achieved highest cell density of 7.15±0.92 × 107 cells/mL on day 10, which was not significantly different (p>0.05) from the G40, G60, and L50 groups, but higher than the control and other treatment groups. Furthermore, alkalinity in the G20 group remained within the range of 130-187 mg/L, which is suitable for cultivation and subsequent use as feed for Moina sp. The pH values of all groups remained consistent, ranging from 7.2-8.8 throughout the experiment. Total ammonia levels remained below 1 mg/L during the first 9 days, increasing in the later period, with no significant differences between the treatment groups. In conclusion, reducing the glucose concentration to 0.1 g/L in the culture medium promoted maximum growth of C. ellipsoidea, while maintaining water quality at an optimal level. This approach offers potential for developing cost-effective algal culture media and scaling up cultivation for commercial production.