Production of lysozyme‐enriched biomass from cheese industry by‐products

Abstract

Cheese whey and cottage cheese whey are by‐products of the milk and cheese industry, resulting from the production of cheese and cottage cheese (ricotta) from milk. They are still rich in organic substances and cannot be discarded into the environment without proper treatment. Whey and cottage cheese whey were used as culture media for some strains of the yeast Kluyveromyces lactis, transformed with the human lysozyme gene. It was found that the yeast strains grew well in both media and produced a considerable amount of recombinant protein. Production kinetics showed that the human lysozyme was produced in a greater amount within 36 h of fermentation (125 μg ml−1vs 25 μg ml−1 in the control) than in the synthetic commercial media used for strain preparation and characterization. The recombinant protein produced was actually shown to be the human lysozyme, using renaturing SDS‐PAGE and Western blot techniques. While producing recombinant protein, the Kluyveromyces strain cleared the cottage cheese whey of most organic substances and produced a considerable amount (almost 3%) of lysozyme‐enriched useful biomass.

A transcriptome analysis of Kluyveromyces lactis growing in cheese whey

“…Further evidence is necessary to relate this change in the transcriptome pattern of genes related to protein glycosylation, post-translational processing and secretion to the convenient use of K. lactis and CW as an efficient expression system for the production of recombinant glycoproteins. Our data give experimental support to the molecular basis of previously reported biotechnological improvements obtained when using CW (Maullu et al, 1999) and also raises the question of what signal present in CW causes this specific change in the transcriptome of the yeast. In silico analysis, using RSA tools as described in Materials and Methods, for exploring the 500 bp upstream regions of 24 K. lactis genes related to N-glycosylation and over-expressed in CW, reveals the existence of two consensuses (CACA-GA and ACATGT) slightly over-represented (3.1-and 3.9-fold, respectively) in reference to random distribution.…”

“…Oxidative stress response Cell Wall Biogenesis ... heterologous protein production by engineered K. lactis strains (Maullu et al, 1999). Secretory proteins in yeast are N-and O-glycosylated while they enter the endoplasmic reticulum.…”

“…Kluyveromyces lactis has the ability to use lactose as a carbon and energy source. This ability together with other advantageous properties including its food-grade status, excellent fermentation characteristics, remarkable secretory capacities and the availability of promoters and vector systems, have made this dairy yeast the protagonist in the modern biotechnological applications of CW (Swinkels, van Ooyen, & Bonekamp, 1993-1994Maullu et al, 1999).…”

Use of magnetic poly(glycidyl methacrylate) monosize beads for the purification of lysozyme in batch system

“…The antibacterial property has been exploited in a number of other applications such as eye drops and wound healing creams [18]. It is used as a food preservative to inhibit growth of Clostridia in cheese [19], spoilage organisms in selected procesed foods [20], and in wine as a substitute for sulfites [21]. It has also been used in gastrointestinal infections and in the treatment of dry-mouth [22].…”

Enhanced human lysozyme production by Kluyveromyces lactis K7 in biofilm reactor coupled with online recovery system

“…Maullu et al [9] produced human lysozyme in cottage cheese whey (5.5% lactose) in shake-flask. Huang and Demirci [10] studied the production of human lysozyme by batch fermentation (110.3 U/mL) and fed-batch fermentation in suspended cell bioreactor (123.6 U/mL).…”