Combination Of Lysozyme Research Articles

Synergid activity of lysozyme and carnosine with antimicrobial drugs in relation to Klebsiella pneumoniae

Klebsiella pneumoniae strains are opportunistic microorganisms that colonize the human gastrointestinal tract and can spread to various tissues and systems of the body, causing a wide range of severe diseases, including pneumonia. The problem of Klebsiella infections has become topical recently due to the spread of hypervirulent and antibiotic-resistant strains in the K. pneumoniae population, which indicated the need to develop modern antimicrobial agents. One of the approaches to combating pathogens of pneumonia is a combination of lysozyme with antimicrobial drugs, which was successfully tested in children’s hospitals in Orenburg. A natural antioxidant and antioxidant, carnosine, is considered as a new candidate in the fight against Klebsiella. A synergistic combination of carnosine with antimicrobial agents against Klebsiella pneumoniae was established in vitro. The results obtained allowed us to expand the range of effective and safe means of combating pathogens of Klebsiella infections.

Enhanced acidogenic fermentation from Al-rich waste activated sludge by combining lysozyme and sodium citrate pretreatment: Perspectives of Al stabilization and enzyme activity

The accumulation of poly aluminum chloride (PAC) in dewatered waste activated sludge (WAS) can cause severe Al pollution and significantly reduce the production of volatile fatty acids (VFAs) from anaerobic fermentation. Herein, the combination of lysozyme and sodium citrate pretreatment was applied to stabilize the aluminum and enhance the VFAs production via anaerobic fermentation. The complexation and stabilization of aluminum by the citrate was efficient, which is conducive to relieving the inhibition of aluminum on lysozymes and other extracellular hydrolases. Compared with the control group, the lysozyme, protease and α-glucosidase activities were obtained at 1.86, 1.72, and 1.15 times, respectively, following the pretreatment. 129.71 mg/g volatile suspended solids (VSS) of soluble proteins and 26.3 mg/g VSS of polysaccharides were obtained within 4 h, together with the degradation of 124 % more proteins and 75 % more polysaccharides within three days. This provided a sufficient number of substrates for VFA production. 588.4 mg COD/g VSS of total VFAs were obtained after the six-day anaerobic fermentation from Al-rich WAS following the combination of lysozyme and sodium citrate pretreatment, which was 7.3 times higher than that of the control group. This study presents a novel approach for enhancing VFA production in anaerobic fermentation as well as reducing risk of Al hazards from Al-rich WAS.

Investigations on the binding properties of hydroxylated polybrominated diphenyl ethers with lysozyme using the multispectral techniques and molecular modeling

As a kind of phenolic chemical with endocrine disrupting potency, hydroxylated polybrominated diphenyl ethers (OH-PBDEs) cause a latent threat to human health from their residue in the environment. Their binding efficiency with lysozyme (LYSO) was studied by molecular simulation combined with fluorescence, UV–vis absorption and circular dichroism (CD), so as to assess their toxicity at the molecular level. Molecular docking data indicate that van der Waals force is the principal interaction force between OH-PBDEs and LYSO. The binding site for 5′-OH-BDE-25 in LYSO is ascertained as the active site, which interaction with the TRP63 and TRP108 residues of LYSO to take shape a strong face-to-face stacked rank (F-shaped). Both 4′-OH-BDE-99 and 3′-OH-BDE-154 display a certain degree of deviation from the active site. Nevertheless, their F-shaped interaction with TRP63 conduce to bind LYSO and stabilize the docking conformation. Combined with dynamics simulation and spectral analysis, the secondary structure of LYSO can be induced by the three kinds of OH-PBDEs. CD spectrum shows that the combination of LYSO and OH-PBDEs will make α- Helix content increased. The combination of OH-PBDEs and LYSO touch upon a static quenching mechanism as a result of steady state fluorescence. The energy decomposition analysis exhibited that LYSO-OH-PBDEs binding site was stable by van der Waals and hydrophobic interaction. As enzyme activity experiments demonstrate that OH-PBDEs can inhibit the activity of LYSO, which is helpful to clarify the molecular toxicity mechanism of OH-PBDEs.

Effect of antimicrobial peptides on planktonic growth, biofilm formation and biofilm-derived bacterial viability of Streptococcus pneumoniae

Streptococcus pneumoniae is a leading cause of pneumonia mortality globally. Pneumococcal disease is often associated with prolonged colonisation of hosts and this process is facilitated by biofilm formation that is largely resistant to conventional antibiotics. We investigated the effects of antimicrobial peptides (AMPs) lysozyme, lactoferrin, LL37 and a combination of all three on planktonic growth, biofilm formation and biofilm-derived bacterial viability by S. pneumoniae, serotype 23F. Planktonic growth and biofilm-derived bacterial viability were determined using standard colony-forming techniques, while biofilm formation was measured using a crystal violet based spectrophotometric method. Relative to controls, lysozyme significantly reduced biofilm formation (0.08 OD vs. 0.10 OD at 570 nm, p = 0.01), while LL37 and the AMP combination increased biofilm formation (0.14 OD vs. 0.10 OD at 570 nm, p = 0.01). The combination of AMPs significantly decreased planktonic growth (1.10 × 108 colony-forming units per millilitres [CFU/mL] vs. 2.13 × 108 CFU/mL, p = 0.02). Biofilm-derived bacterial viability was greatly reduced by exposure to a combination of AMPs (1.05 × 105 CFU/mL vs. 1.12 × 106 CFU/mL, p = 3.60 × 10−8). Streptococcus pneumoniae displays marked resistance to the individual AMPs. A combination of lysozyme, lactoferrin and LL37 effectively inhibited planktonic growth and biofilm-derived bacterial viability; however, persister cell growth was still evident after exposure.

Enhanced Synergistic Antibacterial Activity through a Smart Platform Based on UiO-66 Combined with Photodynamic Therapy and Chemotherapy.

Harmful bacteria have seriously threatened human health and wealth for a long time. Herein, a multifunctional drug delivery system based on UiO-66 was fabricated, and it showed potent synergistic antibacterial effects when used in conjunction with photodynamic therapy and chemotherapy. First, UiO-66-NH2 was prepared via a facile solvothermal method. Then, carboxylic zinc phthalocyanine, a broad-spectrum photosensitizer, was connected to UiO-66-NH2 by amidation. Next, synergistic chemical antibiotic linezolid was loaded in the pores, and lysozyme was coated on the surface by electrostatic interactions. In vitro antibacterial experiments were then carried out to evaluate the antibacterial effects of this system against three kinds of bacteria, Staphylococcus aureus, Escherichia coli, and methicillin-resistant S. aureus (MRSA). The combination of lysozyme, linezolid, and singlet oxygen generated by irradiation of the photosensitizers resulted in a potent antibacterial effect against S. aureus, E. coli, and even MRSA, which demonstrates the synergistic antibacterial efficacy of photodynamic therapy and chemotherapy.

Impact of dietary incorporation of Spirulina (Arthrospira platensis) and exogenous enzymes on broiler performance, carcass traits, and meat quality

This study assessed the effect of Spirulina (Arthrospira platensis), individually and in combination with exogenous enzymes, on growth performance, carcass traits, and meat quality of broiler chickens. One hundred and twenty Ross 308 male chickens were allocated into 40 battery brooders, with 3 birds per cage, and fed ad libitum a corn-based diet during the first 21 D of the trial. The experimental period lasted from day 21 to 35, during which birds were fed 4 different diets: a corn-soybean basal diet, taken as the control group, a basal diet containing 15% Spirulina (MA), a basal diet containing 15% Spirulina plus 0.005% Rovabio Excel AP (MAR), and a basal diet containing 15% Spirulina plus 0.01% lysozyme (MAL). Body weight gain (P < 0.001) and feed conversion rate (P < 0.001) were improved in control chickens, when compared with those fed with Spirulina. In addition, Spirulina increased the length of duodenum plus jejunum in relation to the other treatment (P < 0.01). Chickens on the MAL diet showed a considerable increase in digesta viscosity (P < 0.05) compared with the control group. Breast and thigh meats from chickens fed with Spirulina, with or without the addition of exogenous enzymes, had higher values of yellowness (b*) (P < 0.001), total carotenoids (P < 0.001), and saturated fatty acids (P < 0.001), whereas n-3 polyunsaturated fatty acid (P < 0.01) and α-tocopherol (P < 0.001) decreased, when compared with the control. In conclusion, the incorporation of 15% Spirulina in broiler diets, individually or combined with exogenous enzymes, reduced birds' performance through a higher digesta viscosity, which is likely associated with the gelation of microalga indigestible proteins. In addition, cell wall of Spirulina was successfully broken by the addition of lysozyme, but not by Rovabio Excel AP. Therefore, we anticipate that the combination of lysozyme with an exogenous specific peptidase could improve the digestibility of proteins from this microalga and avoid their detrimental gelation.

Effects of Lysozyme, Proteinase K, and Cephalosporins on Biofilm Formation by Clinical Isolates of Pseudomonas aeruginosa.

Pseudomonas aeruginosa is an opportunistic pathogen that can form biofilms, which confer resistance to immune clearance and antibacterial treatment. Therefore, effective strategies to prevent biofilm formation are warranted. Here, 103 P. aeruginosa clinical isolates were quantitatively screened for biofilm formation ability via the tissue culture plate method. The effects of lysozyme (hydrolytic enzyme) and proteinase K (protease) on biofilm formation were evaluated at different concentrations. Lysozyme (30 μg/mL), but not proteinase K, significantly inhibited biofilm formation (19% inhibition). Treatment of 24-hour-old biofilms of P. aeruginosa isolates with 50 times the minimum inhibitory concentrations (MICs) of ceftazidime and cefepime significantly decreased the biofilm mass by 32.8% and 44%, respectively. Moreover, the exposure of 24-hour-old biofilms of P. aeruginosa isolates to lysozyme (30 μg/mL) and 50 times MICs of ceftazidime or cefepime resulted in a significant reduction in biofilm mass as compared with the exposure to lysozyme or either antibacterial agent alone. The best antibiofilm effect (49.3%) was observed with the combination of lysozyme (30 μg/mL) and 50 times MIC of cefepime. The promising antibiofilm activity observed after treatment with 50 times MIC of ceftazidime or cefepime alone or in combination with lysozyme (30 μg/mL) is indicative of a novel strategy to eradicate pseudomonal biofilms in intravascular devices and contact lenses.

A comprehensive insight into the combined effects of enzymatic and freeze thawing on the dewatering performance of activated sludge

In this study, the effect of enzymatic (lysozyme) and physical (freeze-thaw) methods alone or in combination conditioning on the sludge dewatering performance were comparatively investigated. After the optimization of the dewatering conditions using response surface methodology (RSM), the joint conditioning achieved the water content (W) of the dewatered sludge of 52.01% at the lysozyme (LZM) dosage of 5.9 × 106 Ug−1 DS, the freezing temperature of -26.56°C and the freezing time of 5.78 h. The variance analysis further demonstrated that LZM dosage and the freezing temperature showed significant interaction. Moreover, the improved dewatering performance was mainly attributed to the destruction of the microbial cell wall and extracellular polymeric substance (EPS) structure by enzymatic conditioning, as well as the larger particle size and compact sludge floc structure due to the freeze-thaw conditioning. It followed by the bound water content of sludge decreased from 7.31 gg−1 DS to 3.84 gg−1 DS, which was beneficial for the enhancement in sludge dewaterability. Therefore, the sludge dewaterability was remarkably improved after LZM in combination with freeze-thaw conditioning.

Conditioning effect of lysozyme combined with freeze-thaw on the municipal sludge dewatering performance

The effects of lysozyme (LZM) and freeze-thaw conditioning, alone or in combination, on sludge dewatering performance were comparatively investigated. After the optimization of the dewatering conditions using response surface methodology (RSM), the co-conditioning exhibited obvious superiority to the separate conditioning in improving the dewaterability of municipal sludge, with the capillary suction time (CST) and the water content (W) of the dewatered sludge reduced to 12 ± 0.5 s and 52.0% ± 0.4% from 61.8 s and 73.0%, respectively. The co-conditioning appeared not only to destroy the structure of extracellular polymeric substance (EPS) and microbial cell wall by virtue of enzymatic conditioning, but it formed larger particles and compact sludge floc structure with the help of freeze-thaw conditioning. Additionally, the bound water content of sludge decreased by 47.5% after co-conditioning, consistent with the enhancement in sludge dewaterability. All the results showed that LZM in combination with freeze-thaw conditioning had a great potential in sludge reduction, providing more opportunity of resource utilization for the dewatered sludge.

Application of enterocin AS-48 as biopreservative in eggs and egg fractions: Synergism through lysozyme

The efficacy of enterocin AS-48 in controlling Bacillus cereus and Staphylococcus aureus in liquid whole egg (LWE), egg white (EW), and egg yolk (EY) at 4 and 28 °C was studied. In LWE, AS-48 yields significant reductions in viable counts of B. cereus with minimum bactericidal concentrations (MBC) of 5 and 0.05 μg/ml respectively at 4 and 28 °C (P < 0.05 and P < 0.01, respectively), notably less than that previously determined in brain heart infusion broth. Results obtained with egg fractions suggest the presence of a compound in EW acting synergistically with AS-48 since, at 4 °C, the MBC for AS-48 was established at 1–2.5 μg/ml. Similar results were obtained for S. aureus in LWE and EW, although the AS-48 MBCs were higher: 5–10 and 1–5 μg/ml respectively at 4 and 28 °C in LWE and 10 μg/ml at 28 °C in EW. In EY, both bacteria showed a much lower susceptibility to AS-48 than in LWE and EW. The combination of lysozyme (8 mg/ml) with AS-48 exerted a synergistic inhibitory effect against B. cereus and S. aureus although this synergy was lower than observed in LWE and EW. This synergy has been also confirmed by electron microscopy observation.

Enhancement of the antimicrobial activity of cinnamon essential oil-loaded electrospun nanofilm by the incorporation of lysozyme

The antimicrobial activity of cinnamon essential oil-based electrospun nanofilm is enhanced by the combination of lysozyme.

Synergistic Antilisterial Effects of Mixtures of Lysozyme and Organic Acids

We investigated the synergistic effects of lysozyme combined with organic acids to inhibit the growth of Listeria monocytogenes . The antilisterial effects of the combination of lysozyme and acetic acid, citric acid, lactic acid, malic acid, or succinic acid were evaluated using the checkerboard method and time-kill assay. The MIC was 25,000 mg/liter for lysozyme, 625 mg/liter for acetic acid, and 1,250 mg/liter for the other acids. The MBC was 10,000 mg/liter for all of the tested organic acids. The combination of lysozyme and each organic acid showed synergistic effects via the checkerboard method; however, the time-kill assay showed synergistic effects for only three combinations of 1,250 mg/liter lysozyme with succinic acid (312 and 625 mg/liter) or malic acid (625 mg/liter). The results of this study indicate that the combination of lysozyme and malic acid or succinic acid can be effectively used as a food preservative to control L. monocytogenes .

Application of preservation strategies to improve the shelf life of spreadable cheese

Abstract Strategies designed to protract the shelf life of spreadable cheese obtained by acid coagulations are presented. First, the effectiveness of different headspace CO 2 and N 2 mixtures on the microbial and sensorial characteristics of the investigated produce was addressed; afterward, the modified atmosphere showing the best performances was combined with different antimicrobial compounds (lysozyme and Na 2 -EDTA; MicroGARD ® 400; potassium sorbate). Headspace gas concentration, pH, sensory quality, dairy spoilage microorganisms and lactic microflora were monitored. The work results suggest that CO 2 at every tested concentration negatively influence the taste of spreadable cheese, while the best performances were recorded for samples packaged under 100% nitrogen that was able to control yeasts and moulds development. The most effective solution to increase the shelf life of spreadable cheese was obtained by the combination of lysozyme and Na 2 -EDTA with the selected MAP, 100% nitrogen, allowing to reach a shelf life of about 26 days confronted to the control samples (6 days).

Effects of Bio-preservative Combined with Partially Frozen Storage on Fresh-keeping of &lt;em&gt;Argopectens irradias&lt;/em&gt; Meat

Treated with lysozyme and nisin and vacuum packed, preservation effect of the bio-preservatives on Argopectens irradias meat under partial freezing condition of -3C has been studied. During the process, Total Bacterial Count (TBC) and some physical and biochemical data had been determined. Results show that after 20 days storage at -3C, Total Volatile Basic Nitrogen (T-VBN) of the Argopectens irradias meat treated with lysozyme and nisin reached 13.28 and 13.98 mg/100 g, respectively which all approached upper control limit by China national sanitary standard, while the test datum of Argopectens irradias meat treated with combination of lysozyme and nisin reached 14.81 mg/100 g after 30 days storage which is 20 days longer than control sample. Storage time of each sample correlate to pH, TBC, T-VBN, Thiobarbituric Acid (TBA) and Ca2+-ATPase activity (p<0.05) of the test meat. Of all test samples, combination treatment with lysozyme and nisin achieved the best preservation effect.

Effect of lysozyme addition on the activity of phages against Vibrio parahaemolyticus

Phage therapy gained increased attention as an alternative to antibiotics in order to control bacterial diseases and prevent the spreading of multidrug-resistant bacteria in aquaculture. In this study, the addition of a lytic enzyme (lysozyme) during phage therapy was evaluated for the first time to control Vibrio infection. Three phages of Vibrio parahaemolyticus (VP-1, VP-2 and VP-3) were used. The results indicate that the combination of lysozyme and phage showed better activity in comparison to the activity of the phage alone. VP-1 and VP-2 phages in the presence of lysozyme were more effective in reducing bacterial concentration (reductions of 4.0 log) than the VP-3 phage (which was the most efficient against Vibrio). The application of phages along with lysozyme can be a very useful strategy to eliminate or reduce fish pathogenic bacteria in aquaculture, namely when less effective phages are available.

Efficacy of Lysozme – Lactoferrin as a bioenhancer (immunomodulator) in the treatment of Tuberculosis

OBJECTIVES Astudy was undertaken i to assess sputum conversion of patients at 15 30 45 and 60 days in patients of sputum positive pulmonary tuberculosis TB with the combination of lysozyme and lactoferrin in comparison to placebo ii to make clinical assessment of these patients and c. to observe hypersensitivity reactions and drug toxicity in both groups.DESIGN Open labelled randomised placebo controlled single blinded trialPATIENTS AND INTERVENTIONS 120 patients of sputum positive pulmonary tuberculosis were enrolled. 2 groups of the study were planned the first for newly diagnosed cases Group 1- 60 patients and the second for re-treatment cases Group 2 - 60 patients. In each group 2 arms each of 30 patients were taken. In both groups patients in Arm ndash 1 were given Lysozyme - lactoferrin capsules containing Lactoferrin 5 mg Lysozyme 15 mg twice daily along with standard primary line anti-TB chemotherapy whereas patients in Arm ndash 2 received placebo capsules instead. The sputum conversion was compared at 15 30 45 and 60 days in each arm in both groups.RESULTS a. In newly diagnosed cases of TB Group 1 Sputum conversion occurred earlier at 15 days 33 and 30 days 84.85 in patients treated with BRM ndash 100 as compared to the group receiving placebo 16.6 and 53.2 at 15 and 30 days respectively . However there was no significant difference in the overall sputum conversion at 60 days 100 in both groups. b In Re-treatment cases Group-2 of TB sputum conversion was consistently higher at 15 days23.3 30 days 50 45 days 90 and 60 days 96.66 with Lysozyme - lactoferrin than with placebo 3.33 at 15 days 16.6 at 30 days 46.6 at 45 days and 66.66 at 60 days respectively . The overall success rate was 96.66 with Lysozyme- lactoferrin and 66.66 with placebo.CONCLUSION The combination of Lysozme and Lactoferrin is an oral non-toxic well tolerated affordable biologic response modifier immunomodulator and it shows promising results in both newly diagnosed as well as Re-treatment cases in terms of early sputum conversion at 15 30 45 and 60 days and overall weight gain . This drug combination can be used as an immunomodulator especially in Retreatment cases where the results are appreciably better than in placebo group

Combined effect of synthetic enterocin CRL35 with cell wall, membrane-acting antibiotics and muranolytic enzymes against Listeria cells

To evaluate the inhibition effectiveness of enterocin CRL35 in combination with cell wall, membrane-acting antibiotics and muranolytic enzymes against the foodborne pathogen Listeria. Synthetic enterocin CRL35 alone and in combination with monensin, bacitracin, gramicidin, mutanolysin and lysozyme were used in this study. Minimal inhibitory concentration (MIC) and fractional inhibitory concentration (FIC) index assays were performed using Listeria innocua 7 and Listeria monocytogenes FBUNT as sensitive strains. Antibiotics showed positive interactions with the bacteriocin in both strains tested. On the other hand, when mutanolysin and enterocin CRL35 were added to resting cells in a buffer system, the lytic effect of mutanolysin was enhanced. However, the addition of mutanolysin showed no effect on the growth of L. innocua 7 cells in a culture medium. Moreover, mutanolysin allowed the overgrowth of L. innocua 7 cells to an OD similar to control cells in the presence of inhibitory concentration of enterocin CRL35. In contrast, the combination of lysozyme and enterocin CRL35 resulted in a 50% inhibition of the L. innocua 7 growth. Based on our results, we conclude that the combination of synthetic enterocin CRL35 with some antibiotics is effective against L. innocua 7 and L. monocytogenes FBUNT cells, and more importantly the amount of these agents to be used was considerably reduced. The effectiveness of the combination of synthetic enterocin CRL35 with muramidases seems to depend on complex environments, and more detailed studies need to be performed to elucidate this issue. Enterocin CRL35 represents a promising agent that not only can ensure the quality and safety of food but it can also be combined with several antimicrobial agents important in the medical field.

Protoplast formation and regeneration in Lactobacillus delbrueckii.

Method for production and regeneration of Lactobacillus delbrueckii protoplasts are described. The protoplasts were obtained by treatment with a mixture of lysozyme and mutanolysin in protoplast buffer at pH 6.5 with different osmotic stabilizers. The protoplasts were regenerated on deMan, Rogosa and Sharpe (MRS) with various osmotic stabilizers. Maximum protoplast formation was obtained in protoplast buffer with sucrose as an osmotic stabilizer using a combination of lysozyme (1 mg/ml) and mutanolysin (10 μg/ml). Maximum protoplast regeneration was obtained on MRS medium with sucrose (0.5 M) as an osmotic stabilizer. The regeneration medium was also applicable to other species of lactobacilli as well. This is, to our knowledge, the first report on protoplast formation and efficient regeneration in case of L. delbrueckii.

A small-scale method for quantitation of carotenoids in bacteria and yeasts

Microbial carotenoids are difficult to extract because of their embedding into a compact matrix and prominent sensitivity to degradation. Especially for carotenoid analysis of bacteria and yeasts, there is lack of information about capability, precision and recovery of the method used. Accordingly, we investigated feasibility, throughput and validity of a new small-scale method using Micrococcus luteus and Rhodotorula glutinis for testing purposes. For disintegration and extraction, we combined primarily mild techniques: enzymatically we used combinations of lysozyme and lipase for bacteria as well as lyticase and lipase for yeasts. Additional mechanical treatment included sonication and freeze-thawing cycles. Chemical treatment with dimethylsulfoxide was applied for yeasts only. For extraction we used a methanol-chloroform mixture stabilized efficiently with butylated hydroxytoluene and alpha-tocopherol. Separation of compounds was achieved with HPLC, applying a binary methanol/ tert-butyl methyl ether gradient on a polymer reversed C30 phase. Substances of interest were detected and identified applying a photodiode-array (PDA) and carotenoids quantitated as all-trans-β-carotene equivalents. For evaluation of recovery and reproducibility of the extraction method, we used β-8′-apo-carotenal as internal standard. The method provides a sensitive tool for the determination of carotenoids from bacteria and yeasts and also for small changes in carotenoid spectrum of a single species. Corequisite large experiments are facilitated by the high throughput of the method.

Biocatalysis of linoleic acid to conjugated linoleic acid

CLA refers to a group of geometrical and positional isomers of linoleic acid (LA) with conjugated double bonds. CLA has been reported to have diverse health benefits and biological properties. Traditional organic synthesis is highly capital-intensive and results in an isomeric mixture of CLA isomers. Biotechnology presents new alternatives to traditional lipid manufacturing methods. The objective of this study was to examine the effect of protein isolation procedures on linoleate isomerase (LAI) recovery from microbial cells and biocatalysis of LA to CLA. Protein isolation experiments were carried out using Lactobacillus acidophilus L1 and two strains of Lactobacillus reuteri (ATCC 23272 and ATCC 55739). Under the same assay conditions, ATCC 55739 had the highest LAI activity among the microbial cultures examined in this study. Efficiency of cell lysis methods, which included various combinations of lysozyme and mutanolysin treatments in combination with sonication and osmotic rupture of cells with liquid nitrogen, was very low. Although treatment of cell material with a detergent (octylthioglucoyranoside) freed a significant amount of LAI activity into the solution, it was not sufficient to recover all the LAI activity from the residual cells. Crude LAI preparations produced mainly the cis-9,trans-11 CLA isomer. Time and substrate/protein ratio had a significant effect on biocatalysis of LA to CLA. It appears that the mechanism and kinetics of enzymatic conversion of LA to CLA are quite complex and requires further research using pure LAI preparations.