“
“Aims:

Statistical optimization of medium components for improved chitinase production by Paenibacillus sp. D1.

Methods and Results:

Urea, K(2)HPO(4), chitin and yeast extract were identified learn more as significant components influencing chitinase production by Paenibacillus sp. D1 using Plackett-Burman method. Response surface methodology (central composite design) was applied for further optimization. The concentrations of medium components for improved chitinase production were as follows (g l-1): urea, 0 center dot 33; K(2)HPO(4),

1 center dot 17; MgSO(4), 0 center dot 3; yeast extract, 0 center dot 65 and chitin, 3 center dot 75. This statistical optimization approach led to the production of LCZ696 93 center dot 2 +/- 0 center dot 58 U ml-1 of chitinase.

Conclusions:

The

important factors controlling the production of chitinase by Paenibacillus sp. D1 were identified as urea, K(2)HPO(4), chitin and yeast extract. Statistical approach was found to be very effective in optimizing the medium components in manageable number of experimental runs with overall 2 center dot 56-fold increase in chitinase production.

Significance and Impact of the Study:

The present investigation provides a report on statistical optimization of medium components for improved chitinase production by Paenibacillus sp. D1. Paenibacillus species are gram-positive, spore-forming bacteria with several PGPR and biocontrol potentials. However, only few reports concerning mycolytic enzyme production especially chitinases are available. Chitinase produced by Paenibacillus sp. D1 represents new source for biotechnological and agricultural use.”
“Aims:

Human bifidobacteria are more sensitive to external environmental factors than animal bifidobacteria, and it is difficult to ensure their stable survival https://www.selleck.cn/products/epz-6438.html in yogurt. The purpose of this investigation was to observe the survival of human bifidobacteria in yogurts produced under

various production conditions.

Methods:

Frozen or lyophilized bifidobacteria starters containing Bifidobacterium longum BB536 originally isolated from an infant, and commercial lyophilized yogurt starters were used for yogurt preparation. After producing yogurts under various conditions, the survival of bifidobacteria in these yogurts over various storage periods was observed.

Results:

Although there were some differences in bifidobacterial survival in yogurt between various production conditions, more than 1 center dot 0 x 107 CFU g-1 of Bif. longum survived in yogurt after 35 days’ storage at 5 degrees C. Lower fermentation temperature (37 degrees C) and inclusion of Lactococcus lactis in the starter significantly (P < 0 center dot 05) improved survival of Bif. longum in the yogurt.

Conclusion:

In this investigation, the human bifidobacterial strain Bif. longum survived adequately in yogurt, although the fermentation temperature and starter composition affect bifidobacterial survival.