# Cyanobacterial Potential for Restoration of Loess Surfaces through Artificially Induced Biocrusts
## 3 Results
### Ex Situ Particle Trapping and Stabilization Study  
#### 3.2.1 Development and Morphology of Biocrusts  
During the simulated dust storms, airborne particles were inserted among the cyanobacterial colonies. This community, composed of organisms (inoculated cyanobacteria (Figure 3A)) and particles, formed hardened and crisp biocrust structures during the dry stage. The biocrusts formed were morphologically changing during the cultivation. Patchy biocrusts with flaky and curled features (Figure 3B, arrow 1) covered most of the surface in the experimental chamber. The non-colonized parts were later occupied by smooth biocrusts (Figure 3B, arrow 2).  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Parameter** & **Variability** & **SS** & **DF** & **MS** & **F-Value** & \(p\)**-Value** \\ \hline \multirow{4}{*}{**Biomass (mg/L)**} & Strain & 255081.4 & 4 & 63770.4 & 806.4 & \textless{}0.00001 \\ \cline{2-7}  & Medium composition & 93918.8 & 1 & 93918.8 & 1187.7 & \textless{}0.00001 \\ \cline{2-7}  & Strain and medium composition & 189539.9 & 4 & 47384.2 & 599.2 & \textless{}0.00001 \\ \cline{2-7}  & Error & 1581.5 & 20 & 79.1 & - & - \\ \hline \multirow{4}{*}{**RPS (mg/L)**} & Strain & 2.2 & 4 & 0.6 & 88.9 & \textless{}0.00001 \\ \cline{2-7}  & Medium composition & 5.3 & 1 & 5.3 & 853.1 & \textless{}0.00001 \\ \cline{2-7}  & Strain and medium composition & 5.3 & 4 & 1.3 & 211.6 & \textless{}0.00001 \\ \cline{2-7}  & Error & 0.1 & 20 & 0.0 & - & - \\ \hline \multirow{4}{*}{**Total polysaccharide (mg/L)**} & Strain & 23.1 & 4 & 5.8 & 61.0 & \textless{}0.00001 \\ \cline{2-7}  & Medium composition & 23.8 & 1 & 23.8 & 251.5 & \textless{}0.000001 \\ \cline{2-7}  & Strain and medium composition & 31.8 & 4 & 7.9 & 84.0 & \textless{}0.00001 \\ \cline{2-7}  & Error & 1.9 & 20 & 0.1 & - & - \\ \hline \multirow{4}{*}{**Viscosity (mPa-s)**} & Strain & 540.3 & 4 & 135.1 & 109.4 & \textless{}0.000001 \\ \cline{2-7}  & Medium composition & 0.4 & 1 & 0.4 & 0.3 & 0.573595 \\ \cline{1-1} \cline{2-7}  & Strain and medium composition & 52.3 & 4 & 13.1 & 10.6 & 0.000090 \\ \cline{1-1} \cline{2-7}  & Error & 24.7 & 20 & 1.2 & - & - \\ \hline \hline \end{tabular}
\end{table}
Table 4: The results of statistical analyses (SS—sum of squares; DF—degrees of freedom; MS—mean square; F-Value—Fisher value; \(p\)-Value—probability value). Two-way analysis of variance (ANOVA) results showing the effect of isolated cyanobacterial strains and medium composition on analyzed parameters.  
As explained in the preceding paragraph and Figure 3, different growth patterns of cyanobacterial colonies were observed. The results of visual observations were the following growth patterns (Figure 4): panel A shows areas of smooth biocrusts, panel B shows an example of intercalated morphotypes consisting of curled, pinnacle and smooth structures, and panel C shows tentacle-like protrusions made of cyanobacterial filaments.  
Biocrusts changed their appearance upon water availability. The volume and the area of the biocrust/biofilm increased after wetting (Figure 5). During dry periods the volume of biocrusts shrank, the colour became more bleached and the surface became discontinuous over the sediment (Figure 5A). Upon wetting an increase in the biovolume and a transformation of the structure from discontinuous (Figure 5A) to continuous (Figure 5B) were observed. The discontinuous appearance (Figure 5A) became continuous, thicker, and dark-green coloured upon wetting (Figure 5B).