Quick and low cost immobilization of proteinases on polyesters: Comparison of lactobacilli cell-envelope proteinase and trypsin for protein degradation

Effect of medium composition on cell envelope proteinase production by Lactobacillus plantarum LP69

Cell envelope proteases (CEPs) can break down milk protein into peptides with different functions, which are of great benefit to human health. Therefore, the high-yield CEPs of Lactobacillus plantarum have the potential to produce functional dairy products. In previous experiments, we found that Na2HPO4, inulin, casein peptone and leucine have significant effects on CEP production by Lactobacillus plantarum LP69. So we proceeded to optimize the composition of the CEP-producing culture medium of L. plantarum through Box-Behnken design and response surface methodology. The protease activity, protein content and specific activity of CEPs produced by L. plantarum by inulin (0.2, 0.3, 0.4 %), casein peptone (0.4, 0.6, 0.8 %), Na2HPO4 (0.50, 0.52, 0.54 %) and leucine (14, 16, 18 mg/L) were evaluated. The optimal ratio of medium is 0.4 % inulin, 0.66 % casein peptone, 0.5 % Na2HPO4 and 14.04 mg/L Leucine. The final enzyme activity reached (24.46±0.81) U/mL, and the specific activity reached (1.41±0.46) U/mg.

Cell-envelope proteinases from lactic acid bacteria: Biochemical features and biotechnological applications

Proteins displayed on the cell surface of lactic acid bacteria (LAB) perform diverse and important biochemical roles. Among these, the cell-envelope proteinases (CEPs) are one of the most widely studied and most exploited for biotechnological applications. CEPs are important players in the proteolytic system of LAB, because they are required by LAB to degrade proteins in the growth media into peptides and/or amino acids required for the nitrogen nutrition of LAB. The most important area of application of CEPs is therefore in protein hydrolysis, especially in dairy products. Also, the physical location of CEPs (i.e., being cell-envelope anchored) allows for relatively easy downstream processing (e.g., extraction) of CEPs. This review describes the biochemical features and organization of CEPs and how this fits them for the purpose of protein hydrolysis. It begins with a focus on the genetic organization and expression of CEPs. The catalytic behavior and cleavage specificities of CEPs from various LAB are also discussed. Following this, the extraction and purification of most CEPs reported to date is described. The industrial applications of CEPs in food technology, health promotion, as well as in the growing area of water purification are discussed. Techniques for improving the production and catalytic efficiency of CEPs are also given an important place in this review.

Polyamine-induced tannic acid co-deposition on magnetic nanoparticles for enzyme immobilization and efficient biodiesel production catalysed by an immobilized enzyme under an alternating magnetic field

In this study, we report facile, rapid and stable polyamine TEPA-induced tannic acid (TA) co-deposition system-functionalized magnetic nanoparticles, which may provide an improved nanoplatform for enzyme immobilization.

Novel Application of Magnetic Protein: Convenient One-Step Purification and Immobilization of Proteins

Recently, a magnetic protein was discovered, and a multimeric magnetosensing complex was validated, which may form the basis of magnetoreception. In this study, the magnetic protein was firstly used in biotechnology application, and a novel convenient one-step purification and immobilization method was established. A universal vector and three linker patterns were developed for fusion expression of magnetic protein and target protein. The magnetic protein was absorbed by iron beads, followed by target protein aggregation, purification, and immobilization. GFP, employed as a reporter protein, was successfully purified from cell lysate. Subsequently, three enzymes (lipase, α-L-arabinofuranosidase, pullulanase) with different molecular sizes testified the versatility of this magnetic-based approach. The specific activities of the purified enzymes were distinctly higher than those of the traditionally purified enzymes using affinity chromatography. The lipase immobilized on iron beads presented improved thermostability and enhanced pH tolerance compared to the free enzyme. The immobilized lipase could be easily recovered and reused for maximum utilization. After 20 cycles of reutilization, the magnetically immobilized lipase retained 71% of its initial activity. This investigation may help introduce magnetic protein into biotechnology applications, and the one-step purification and immobilization method may serve to illustrate an economically viable process for industry.

Nanostructuring Biomaterials with Specific Activities towards Digestive Enzymes for Controlled Gastrointestinal Absorption of Lipophilic Bioactive Molecules

This review describes the development of novel lipid-based biomaterials that modulate fat digestion for the enhanced uptake of encapsulated lipophilic bioactive compounds (e.g. drugs and vitamins). Specific focus is directed towards analysing how key material characteristics affect the biological function of digestive lipases and manipulate lipolytic digestion. The mechanism of lipase action is a complex, interfacial process, whereby hydrolysis can be controlled by the ability for lipase to access and adsorb to the lipid-in-water interface. However, significant conjecture exists within the literature regarding parameters that influence the activities of digestive lipases. Important findings from recent investigations that strategically examined the interplay between the interfacial composition of the lipid microenvironment and lipolysis kinetics in simulated biophysical environments are presented. The correlation between lipolysis and the rate of solubilisation and absorption of lipophilic compounds in the gastrointestinal tract (GIT) is detailed. Greater insights into the mechanism of lipase action have provided a new approach for designing colloidal carriers that orally deliver poorly soluble compounds, directly impacting the pharmaceutical and food industries.