## 2 Materials and Methods
### Data Analysis  
Univariate analysis of variance was carried out and the statistical comparisons were done with the Bonferroni test (multiple comparison test of the means and to determine which means are significantly different) using a statistical package program (GraphPad Prism(r) 5.03 software for Windows). \(p\) value < 0.05 was regarded as statistically different between means and \(p\) value < 0.001 as statistically highly significant using the \(t\)-test. The scoring of each fraction and subsequent clusters were based on a standard deviation of \(\pm\)0.5 SD (1 SD total) of the mean of the data set Figure S5 (Supplementary Material).  
The strength and durability testing screens consisted of the following, resistance to compression, abrasion, erosion, and water absorption. Each fraction was rated on a scale from 1 to 4, where 1 represented lowest and 4 the highest score. The cumulative score (Si) was calculated by averaging the four tests, bearing in mind that each test had an equal importance (i.e., 25%) to the selection. The maximum score was 100%, where a fraction would need to score 4/4 for each test (Equation (1)). The final selection was made based on the desirability of each fraction on all parameters tested. All scores obtained for each individual strength test were added to give an overall performance effect.  
\[\text{Cumulative score (Si)}=0.25\times\left[\text{(Si, 1+Si, 2+Si, 3+Si, 4)/(Si,max)}\right]\times 100 \tag{1}\]  
where,  
Si,1 = Compression test score  
Si,2 = Abrasion test score  
Si,3 = Erosion test score  
Si,4 = Water absorption test score  
Si,max = 4 (max score, 16 across all tests)  
Figure 2: Particle size distribution curve (soil weathered granite).  
The cumulative score results were separated into two growth stages (growth stage 1: vegetative phase; and growth stage 2: sporulation phase) for each soil type. The selection phase focused on the fermentation phase (vegetative and spores) and the soil type. Using the novel statistical strategy designed for this study, the criterion provides a selective basis of the best performing component (fraction) from each parameter that was set in the high-throughput screening tests (compression stress, abrasion, erosion, and water absorption tests). Once the selection of components (fractions) was completed, the best performer, including the commercial standard, was tested at large-scale. This includes compaction studies, erosion, and abrasion tests.  
Technology design and development should not only meet technical requirements but should also provide other benefits over the traditional methods and existing technologies. The question is whether the use of the new technology is going to be cost effective and give financial, social or environmental benefit over the existing technology. Critical aspects to consider include cost, performance, and time. A cost equation is shown to further justify that cost, with time and performance is a primary measure in the criteria for final selection of the best performing fractions obtained from the various fermentation phases (i.e., batch 1 and batch 2) (Equation (2)).  
\[\text{Relative production cost}:\text{Ct}=(\text{C}\text{c}_{1}+\text{C}\text{c}_{2}+ \ldots+\text{C}\text{n})+(\text{C}\text{u}_{1}+\text{C}\text{u}_{2}+\ldots+ \text{C}\text{u}_{\text{n}})+(\text{C}\text{I}_{1}+\text{C}\text{I}_{2}+\ldots +\text{C}\text{l}_{\text{n}}) \tag{2}\]  
where,  
Ct = Total production cost  
Cc = Cost of raw materials and consumables  
Cu = Cost of utilities  
Cl = Cost of labour  
n = Cost components