β-galactosidase (EC 3.2.1.23) is one of the widely used enzymes for lactose-free milk production and whey permeate treatment. Enzymes can be obtained from microorganisms, plants and animals. Nowadays, microorganisms are becoming an important source for production of commercially available enzymes, which are of great interest and offer several advantages such as easy handling and high production yield. The aim of this review was to summarize findings of research articles on the application of commercially available β-galactosidase preparates in dairy industry, to analyse and compare the most suitable β-galactosidase commercial preparates for lactose hydrolysis. The results showed that the main factor to choose an appropriate β-galactosidase for lactose hydrolysis was reaction condition. Enzymes from microorganisms contain a wide range of optimal pH from 4.0 (Penicillium simplicissimum and Aspergillus niger) to 8.5 (Bacillus subtilis). The greatest commercial potential has enzymes obtained from fungi (Aspergillus oryzae and Aspergillus niger) and yeasts (Kluyveromyces lactis and Kluyveromyces fragilis). Fungal origin enzymes are more suitable for the hydrolysis of lactose in acid whey due to its acidic pH but yeasts origin enzymes for milk and sweet whey. In the study, commercial preparates from different suppliers with the purpose to analyse their lactose hydrolysis potential and give more detailed characteristics of each preparate advantages and drawbacks were also summarized.

Lactobionic acid is a high value added compound industrially produced through energy intensive chemical synthesis, which uses costly metal catalysts, like gold and platinum. In the next years, biotechnological production of lactobionic acid can be supposed to take the full transition to the manufacturing stage. Productivity of lactobionic acid by microbial production can be affected by various factors – choice of microorganism and its concentration, supply of oxygen, temperature, substrate, cultivation method, pH and aeration rate. The aim was to review research findings for lactobionic acid production as well innovative and efficient technology solutions for self-costs reducing. Whey was recommended as a cheap and suitable substrate for the lactobionic acid production. Whey processing has been advised with Pseudonomas teatrolens in 28 °C and in pH 6 to 7 for yielding the highest productivity. The increasing commercial importance urges the progression of schemes for lactobionic acid biotechnological manufacturing.

This article presents the results of a comparative evaluation of preventive treatment of udder with probiotic agents: ‘Dipal’ (manufacturer DeLaval - Sweden), ‘Zorka’ (manufacturer «NPP Farmaks» - Russia). We have received data on the effects of probiotic preparation on quality of milk and number of somatic cells in milk. Research has been conducted in two dairy farms of Almaty region of the Republic of Kazakhstan. Lactobacillus acidophilus 05ch - isolated from shubat (South Kazakhstan region, Turkestan). Lactococcus lactis 010k - isolated from three-day kumys (Zhambyl region, Merke). These probiotics are used as a means for sanitary treatment of the udder of cows. Thus, the procedure of determining the antagonistic activity revealed their high activity against both gram-negative and gram-positive microorganisms, notably Staphylococcus aureus (10-13 mm), Escherichia coli (12 mm), Proteus vulgaris (10-14 mm), Salmonella abortus ovis (11-13 mm). Significant changes in the milk indices can be found in the experimental group: 9.1% rise of lactose, and 7.2% reduction of protein. The level of protein increased by 4.1% , whereas the amount of lactose, on the contrary, went down 1.6%, which may be indicative of the increase in the content of serum protein when the udder is inflamed. The examination of the milk obtained from the cows of the control and experimental groups showed a nearly double reduction in the number of somatic cells from 488.00 down to 178.000 thousand, which was caused by the daily treatment of cows by probiotic cultures during 2 weeks.