## 1 Introduction
The claim by most of the suppliers of these products that it improves almost any soil type to a suitable quality for road construction, as well as the mixed results of the claims, has created a barrier to acceptability. It is important to assess the efficiency and efficacy of these products in a large-scale project, which may lead to modification of these existing products that will allow them to be acceptable to the industry. The proposal is the use of microbial biotechnology techniques, to drive research towards investigating alternative bio-inspired formulated materials, such as, microbial biomass, microbial cements, bio-polymers, and bioplastics [5]. With more research focusing on microbial methods, bio-based processes, and products, it is important to consider bio-stabilisers as possible alternatives to conventional chemical methods for construction applications. A well-known example is the use of highly active urease producing bacteria in a cementation process to bind loose soil particles together (i.e., microbially induced calcium carbonate precipitation (MICCP) [6; 7]. This process provides sufficient evidence in mechanistic action of _Bacillus_ spp. on the improved mechanical properties of treated soils [8]. Even though several studies have investigated microbial biocement, there is still limited knowledge and standardisationfor the implementation of new biological products and processes (testing of in situ/in-place soil and pavement materials, in terms of strength and performance). Recently, there has been revived scientific interest in the use of extracellular polymeric substances (EPS) (i.e., bio-polymers) produced by _Bacillus_ spp., with industry benefit [9]. Extracellular polysaccharides (exopolysaccharide) and proteins are the major components formed in these EPS systems [10]. One of the functional roles of the EPS matrix is their capacity to aggregate soil particles, since the slimy texture of EPS and ionic charges act as a 'glue' attaching clay minerals, ions, and solid particles together [11]. Similarly, studies have identified different types of bio-polymers (i.e., xanthan gum, guar gum, modified starches, glucan, casein, and sodium caseinate) that can improve the engineering properties of typical soils (sand, silt, and clay) [12; 13]. Studies show that fermentation processes using the _Bacillus_ spp. can produce similar bio-flocculent material, which are nontoxic and environmentally friendly compounds, comparative to conventional synthetic flocculants. Bio-flocculants have been produced, using _B. licheniformis_[10] and _Halomonas_ spp., also known for their thermostability (4-95 \({}^{\circ}\)C) [14]; both show great potential as candidates for selection and evaluation in future studies [14; 15]. The aim of the paper is to evaluate and demonstrate the use of _Bacillus licheniformis_ as potential bio-based solution for soil stabilisation. In this study, the fractions (polar and non-polar compounds) are hypothesised as the most suitable for the potential application on construction materials (i.e., fine grained soil and wearing course). The main objectives include, (a) evaluation of 18 macro-components (fractions) produced by _B. licheniformis_ via small-scale strength testing, (b) the evaluation of appropriate microbial derived macro-components (fractions) using statistical assessment and novel matrices for selection of the best performers, (c) large-scale industry validation of the selected prototype/s.