Microbial community development of biofilm in Amaranth decolourization technology analysed by FISH

Figures & data

Table 1. Mean values of the key technological parameters in the early and the late phase of the biofilter functioning.

Parameter	Early phase (191 h) – inflow Amaranth concentration 10–30 mg/L	Late phase (455 h) – inflow Amaranth concentration 30–45 mg/L
Flow rate (mL/h)	20.58	24.41
Efficiency of Amaranth removal (%)	92.40	93.35
Rate of Amaranth removal (mg/mL h)	0.428	0.944
COD (mgO/L)	401.21	374.71
TOC (mg/L)	114.20	107.51

Figure 1. Design of the experiment and description of the parameters of the water treatment process.

Figure 2. Distribution of the amount of key functional groups of microorganisms in the biofilm (azo-degrading bacteria (AzoD), aerobic heterotrophs (АН) and genus Pseudomonas (Pseud. sp.)). Data are obtained using plate count techniques.

Table 2. Key enzyme activities for Amaranth biodegradation: azoreductase (AzoR), succinate dehydrogenase (SDH), catechol-1,2-dioxygenase (C12DO) and catechol-2,3-dioxygenase (C23DO) in the early and the late phase of the process.

	Early phase (191 h) – inflow Amaranth concentration 10–30 mg/L			Late phase (455 h) – inflow Amaranth concentration 30–45 mg/L
Layer	Upper layer	Middle layer	Bottom layer	Upper layer	Middle layer	Bottom layer
AzoR (μmol/min mg protein)	3.47	7.98	6.57	9.33	3.36	10.00
SDH (μmol/min mg protein)	0.80	0.24	0.09	0.39	0.68	0.18
C12DO (μmol/min mg protein)	–	–	0.05	2.37	3.95	1.96
C23DO (μmol/min mg protein)	–	–	–	1.62	0.92	2.67

Table 3. FISH pictures of the biofilm community. Each object is shown stained with DAPI (blue colour) and with fluorescent probe specific for the genus Pseudomonas (red colour). The samples are taken from the three layers of the biofilter in the early (191 h) and in the late (455 h) phase of the experiment.

Figure 3. Pseudomonas spp. ratio to the total quantity of the microorganisms calculated on the basis of (a) FISH and (b) standard plate count techniques.