Biological Microbicides

[BIOTECH • 18.03.2014]

»Biological microbicides made from algae and plants used in preserving cosmetic formulations« have been the focus of IGV Biotech’s project work over the past three years. The objective is for natural preservatives both to replace chemical and synthetic preservatives in conventional cosmetics as well as to meet the strict requirements of natural cosmetics. In the project promoted by the ILB under registration number 80139583, microalgae as well as macroalgae and selected plants were investigated relative to their microbicidal content.

In the course of evolution, natural systems have developed numerous chemical defence strategies against harmful microorganisms such as bacteria and fungi. In the case of algae and plants these strategies include the synthesis of a variety of compounds such as terpenes, phenolic acids, acetophenone, farnesol, bisabolol and also various flavones which have an antimicrobial effect.

In the course of a wide-ranging screening programme, aqueous and ethanolic extracts as well as extracts from high-pressure CO2 extraction were produced from selected algae and plants and tested in relation to their properties in resisting bacteria, yeasts and mildew. Effective individual extracts from macro- and microalgae were combined with those from plants with the aim of achieving resistance against the entire spectrum of bacteria by means of an additive or combined effect.

Stress tests carried out on preservatives attest that cosmetic formulations can be effectively protected against microbial contamination by using extract compounds at concentrations of 1-2%. The reduction in test bacteria fulfils the A criteria of the requirements of the European Pharmacopeia for preparations for topical use (recommended efficacy).

Moreover the extract compounds were tested in relation to their cosmetic efficacy and skin tolerance. The selected extracts demonstrated statistically significant regenerative and protective effects with respect to induced skin irritations (redness). In the assessment of anti-aging effects regular use of the test products led to a reduction in wrinkle depth, an increase in skin moisture levels and firmness as well as to an improvement in skin elasticity and smoothness together with proven good levels of skin tolerance.


The project was funded by the Brandenburg Ministry of Economic and European Affairs and the EU. Responsibility for the content of the publication rests with the author.