Production of Lactic Acid from Whey Using Immobilized ‎Mixed Culture of Streptococcus thermophilus and Lactobacillus ‎bulgaricus

Sahar Adnan Sheet(1) and Waleed Ahmed Mahmood*(1)

(1). Faculty of Agriculture and Forestry, University of Mosul, Iraq.

 (*Corresponding author: Dr. Waleed Ahmed Mahmood, E-Mail: waleedahmed53@yahoo.com).

Received: 12/01/2020                               Accepted: 12/04/2020

Abstract

This study was carried out at Faculty of Agriculture and Forestry, University of Mosul during 2018 and 2019 seasons. Lactic acid was produced from cheese whey of buffalo’s milk by a mixed culture of Streptococcus thermophilus and Lactobacillus bulgaricus immobilized in calcium alginate gel by using batch fermentation. Some factors affecting immobilization efficiency and lactic acid productivity were studied. Results indicated that the concentration of 2% sodium alginate in the cell suspension resulted in maximum immobilization efficiency and acid production with significant differences from the other used concentrations (1 and 2%). Maximum acid productivity and immobilization efficiency were obtained upon using calcium chloride with concentrations of 4 and 5%, respectively. Beads diameter of 3 mm resulted in the highest immobilization efficiency and acid productivity. 45-60 minutes of beads solidification time were found suitable to obtain high immobilization efficiency and lactic acid productivity. Results showed that low inoculum concentration (5×107 cell/ml) was preferred for obtaining the highest immobilization efficiency, which was significantly dropped upon increasing of inoculum concentration. Maximum lactic acid production was obtained by using inoculum concentration of 20×107 cell/ml with non-significant differences over the range of 10-25×107 cell/ml. Immobilized cells were reused for four runs and a significant loss in activity was observed during the successive runs.

Key words: Lactic acid,Streptococcus thermophilus, Lactobacillus bulgaricus, whey, Immobilized cells.

Full paper in Arabic: PDF

Using Grape Pruning and Apple Trees Pruning Residues With the Addition of Nutrient Solution in Feeding Growing Jabaly Goats, Syria.

Rana Alshohefe*(1) Ali Alhawarin(1) Wathek Takea(1) and Jawad Sharaf(1)

(1). Era Research Station for Jabaly Goat, Scientific Research Center in Swaida, General Commission for Scientific and Agricultural Research (GCSAR), Swaida, Syria.

(*Corresponding author: Rana Alshohefe, Era Research Station for Jabaly Goat, Scientific Agricultural Research Center in Swaida, (GCSAR), Swaida, Syria. E-mail: rraana81@gmail.com Tel: 016248256).

Received: 04/02/ 2015         Accepted: 07/05/ 2015

Abstract

The study was conducted at Era Research Station, Swaida Scientific Agricultural Research Center, GCSAR, Swaida, Syria, to improve growing of Jabaly goat strain (Swaida) during 2012 by using grapes and apple trees pruning residues with the addition of nutrient solution (80% whey + 20% molasses) with rate 40% as diet in feeding growing Jabaly goat. The research was conducted using (27) heads of males growing goats, and (27) heads of females, both males and females were randomly divided into (3) groups, each group fed on the same protein and energy, as follow: G1: Which was fed on 75% concentrated diets + 25% straw with the addition of nutrient solution (control), G2: That was fed on 75% concentrated diets + 25% apple tree pruning residues with the addition of nutrient solution, and G3: Which was fed on 75% concentrated diets + 25% grape pruning residues with the addition of nutrient solution. Results for males showed significant difference (p≤0.05) in increasing weight, conversion efficiency, and cost of 1kg of body weight (p≤0.01). G3 surpassed both the control and G2 groups. For females the results showed no significant difference in the increasing weight, while there were a significant difference in conversion efficiency, and the cost of 1kg in body weight (p≤0.01). Also G3 group surpassed the control and G2 groups. The conclusion is that, the addition of grape and apple trees pruning residues with the addition of nutrient solution of 25% to the growing diet, increased body weight and decreased the cost of production significantly.
Keywords: Jabaly goat, Apple pruning residues, Grape pruning residues, Whey, Nutrient solution, Syria.

Full paper in Arabic:استخدام بقايا تقليم العنب والتفاح المعاملة بالسائل المغذي في تغذية الماعز الجبلي النامي، سورية