Weakening of the Gram-negative bacterial outer membrane - A tool for increasing microbiological safety

Gram-negative bacteria are harmful in various surroundings. In the food industy their metabolites are potential cause of spoilage and this group also includes many severe or potential pathogens, such as Salmonella. Due to their ability to produce biofilms Gram-negative bacteria also cause problems in many industrial processes as well as in clinical surroundings. Control of Gram-negative bacteria is hampered by the outer membrane (OM) in the outermost layer of the cells. This layer is an intrinsic barrier for many hydrophobic agents and macromolecules. Permeabilizers are compounds that weaken OM and can thus increase the activity of antimicrobials by facililating entry of hydrophobic compounds and macromolecules into the cell where they can reach their target sites and inhibit or destroy cellular functions. The work described in this thesis shows that lactic acid acts as a permeabilizer and destabilizes the OM of Gram-negative bacteria. In addition, organic acids present in berriers, i.e. malic, sorbic and benzoic acid, were shown to weaken the OM of Gram-negative bacteria. Organic acids can poteniate the antimicrobial activity of other compounds. Microbial colonic degradation products of plant-derived phenolic compounds (3,4-dihydroxyphenylacetic acid, 3-hydroxyphenylacetic acid, 3,4-dihydroxyphenylpropionic acid, 4-hydroxyphenylpropionic acid, 3-phenylpropionic acid and 3-hydroxyphenylpropionic acid) efficiently destabilized OM of Salmonella. The studies increase our understanding of the mechanism of action of the classical chelator, ethylenediaminetetra-acetic acid (EDTA). In addition, the results indicate that the biocidic activity of benzalkonium chloride against Pseudomonas can be increased by combined use with polyethylenimine (PEI). In addition to PEI, several other potential permeabilizers, such as succimer, were shown to destabilize the OM of Gram-negative bacteria. Furthermore, combination of the results obtained from various permeability assays (e.g. uptake of a hydrophobic probe, sensitization to hydrophobic antibiotics and detergents, release of lipopolysaccharide (LPS) and LPS-specific fatty acids) with atomic force microscopy (AFM) image results increases our knowledge of the action of permeabilizers.

Increasing Knowledge Focus - a Means for Entrepreneurs to Remain on a Growth Path: Essays on the Role and Nature of Knowledge Management in Finnish SMEs (summary section only)

This study explores the role and nature of knowledge management (KM) in small and medium-sized companies (SMEs). Even though the role of knowledge as a competitive advantage is commonly recognized in the SME sector, almost no attention has been paid to the managing and developing of knowledge in SMEs. This thesis consists of three different sub-studies that were reported in four individual essays. The results of the questionnaire study indicate that nearly all companies that responded to the questionnaire (N = 108) found intangible assets, i.e. knowledge resources to be their main source of competitive advantage. However, only less than a third of the companies actively deal with knowledge management. The results also indicate a significant correlation between activity in knowledge management and sustainable organic growth of the company. The interview study (N = 10) explored the context and motives of the SMEs for managing their intangible assets, and the concrete practices of knowledge management. It turned out that KM facilitated change management, clarification of the vision and new strategy formulation. All the interviewed companies were aiming at improved innovation process, new ways of doing business and attaining an increased “knowledge focus” in their business. Nearly all also aspired to grow significantly. Thus, KM provides a strategy for these SMEs to guarantee their survival and sustainability in the turbulent markets. The action research was a process to assess and develop intangible resources in three companies. The experienced benefits were the clarification of future focus and strategy, creation of a common language to discuss strategic issues within the company, as well as improved balance of different categories of intangible assets. After the process all the case companies had developed in the chosen key areas. Thus, by systematic knowledge management the implementation of new strategic orientation (knowledge focusing) was facilitated. The findings can be summarized in two main points. First, knowledge management seems to serve the purpose of change, renewal and new strategic orientation in the SMEs. It also seems to be closely related to organic growth and innovation. All of these factors can be considered dimensions of entrepreneurship. Second, the conscious development of intangible assets can increase the balance of different categories of intangible assets and the overall knowledge focusing of business. In the case companies, this in turn facilitated the path to the improved overall performance.

Increasing forestry investments by means of public policy programs.

XVIII IUFRO World Congress, Ljubljana 1986.