Ectoine production using inexpensive and renewable biomass resources has attracted great interest among the researchers due to the low yields of ectoine in current fermentation approaches that complicate the large-scale production of ectoine. In this study, ectoine was produced from corn steep liquor (CSL) and soybean hydrolysate (SH) in replacement to yeast extract as the nitrogen sources for the fermentation process. To enhance the bacterial growth and ectoine production, biotin was added to the Halomonas salina fermentation media. In addition, the effects addition of surfactants such as Tween 80 and saponin on the ectoine production were also investigated. Results showed that both the CSL and SH can be used as the nitrogen source substitutes in the fermentation media. Higher amount of ectoine (1781.9 mg L-1) was produced in shake flask culture with SH-containing media as compared to CSL-containing media. A total of 2537.0 mg L-1 of ectoine was produced at pH 7 when SH-containing media was applied in the 2 L batch fermentation. Moreover, highest amount of ectoine (1802.0 mg L-1) was recorded in the SH-containing shake flask culture with addition of 0.2 μm mL-1 biotin. This study demonstrated the efficacy of industrial waste as the nutrient supplement for the fermentation of ectoine production.
This study investigated the influence of the intention to lean the body forward on spatiotemporal and ground reaction force variables during the acceleration phase of a sprint. Fourteen active adults performed two 50 m sprints (with and without the intention to lean), during which spatiotemporal variables and impulses were obtained using a long force platform system. Effect size (Cohen's d) was used to examine the differences between the two trials. We found that running speed and net anteroposterior impulse did not change by the intention for all steps. However, step frequency increased in the initial two steps through decreases in support time and flight time by the intention. Moreover, these shorter support and flight times were caused by a decrease in the vertical impulse. The propulsive impulse did not change during the initial part of acceleration phase, but the braking impulse decreased at the first step. This study demonstrates that an intention to lean the body forward leads to a smaller braking impulse and a higher step frequency through shorter support and flight times and a smaller vertical impulse during the initial part of the acceleration phase of a sprint.