Quantification of Sulfate-reducing Bacteria in Industrial Wastewater,by Real-time Polymerase Chain Reaction (PCR) Using <Emphasis Type="Italic">dsrA</Emphasis> and <Emphasis Type="Italic">apsA</Emphasis> Genes

Real-time polymerase chain reaction (PCR) is considered a highly sensitive method for the quantification of microbial organisms in environmental samples. This study was conducted to evaluate real-time PCR with SybrGreen detection as a quantification method for sulfate-reducing bacteria (SRB) in industrial wastewater produced by several chemical industries. We designed four sets of primers and developed standard curves based on genomic DNA of Desulfovibrio vulgaris from pure culture and on plasmids containing dissimilatory sulfate reductase (dsrA) or adenosine-5′-phosphosulfate reductase (apsA) genes of SRB. All the standard curves, two for dsrA and two for apsA genes, had a linear range between 0.95 × 10² and 9.5 × 10⁶ copies/μL and between 1.2 × 10³ and 1.2 × 10⁷ copies/μL, respectively. The theoretical copy numbers of the tenfold dilutions of D. vulgaris genomic DNA were best estimated (between 2.7 to 10.5 times higher than theoretical numbers) by the standard curve with DSR1F and RH3-dsr-R primers. To mimic the effect of foreign DNA in environmental samples, serial dilutions of D. vulgaris genomic DNA were mixed with Escherichia coli chromosomal DNA (40 ng per assay). This influenced neither PCR amplification nor the quantification of target DNA. Industrial wastewater was sampled during a 15-month period and analyzed for the presence of SRB, based on dsrA gene amplification. SRB displayed a higher abundance during the summer (about 10⁷–10⁸ targets mL⁻¹) and lower during the winter (about 10⁴–10⁵ targets mL⁻¹). The results indicate that our real-time PCR approach can be used for detection of uncultured SRB and will provide valuable information related to the abundance of SRB in durable environmental samples, such as complex and saline industrial wastewaters.     

Development of a real-time TaqMan assay to detect <Emphasis Type="Italic">mendocina</Emphasis> sublineage <Emphasis Type="Italic">Pseudomonas</Emphasis> species in contaminated metalworking fluids

A TaqMan quantitative real-time polymerase chain reaction (qPCR) assay was developed for the detection and enumeration of three Pseudomonas species belonging to the mendocina sublineage (P. oleovorans, P. pseudoalcaligenes, and P. oleovorans subsp. lubricantis) found in contaminated metalworking fluids (MWFs). These microbes are the primary colonizers and serve as indicator organisms of biodegradation of used MWFs. Molecular techniques such as qPCR are preferred for the detection of these microbes since they grow poorly on typical growth media such as R2A agar and Pseudomonas isolation agar (PIA). Traditional culturing techniques not only underestimate the actual distribution of these bacteria but are also time-consuming. The primer–probe pair developed from gyrase B (gyrB) sequences of the targeted bacteria was highly sensitive and specific for the three species. qPCR was performed with both whole cell and genomic DNA to confirm the specificity and sensitivity of the assay. The sensitivity of the assay was 10¹ colony forming units (CFU)/ml for whole cell and 13.7 fg with genomic DNA. The primer–probe pair was successful in determining concentrations from used MWF samples, indicating levels between 2.9 × 10³ and 3.9 × 10⁶ CFU/ml. In contrast, the total count of Pseudomonas sp. recovered on PIA was in the range of <1.0 × 10¹ to 1.4 × 10⁵ CFU/ml for the same samples. Based on these results from the qPCR assay, the designed TaqMan primer–probe pair can be efficiently used for rapid (within 2 h) determination of the distribution of these species of Pseudomonas in contaminated MWFs.     

Electromagnetic field effects on <Emphasis Type="Italic">Artemia</Emphasis> hatching and chromatin state

The influence of magnetic fields on hatching and chromatin state of brine shrimp, Artemia sp., was investigated. Dry Artemia cysts were exposed to a magnetic field of intensity 25 mT for 10 min. The magnetic field was applied in different variants: constant field, rotating field of different directions (right-handed and left-handed) and different magnet polarization. The effect of ultra wideband pulse radiation and microwave radiation was also investigated. The energy density on the surface of object exposed to ultra wideband pulse radiation was 10⁻², 10⁻³, 10⁻⁴, 10⁻⁵ and 10⁻⁶ W/cm², the power of microwave radiation was 10⁻⁴ and 10⁻⁵ W/cm², exposure time - 10 s. After incubation of the cysts for 48 hours in sea water the hatching percentage of Artemia from exposed cysts was higher than in controls. The number of heterochromatin granules was significantly higher in the nauplia (newborn larvae of Artemia) developed from cysts that had been exposed to magnetic and electromagnetic fields. The data obtained demonstrate an increase in percentage hatching of Artemia cysts after treatment with magnetic and electromagnetic fields and chromatin condensation in nauplia. We have also shown different effects of right-handed and left-handed rotating magnetic fields on these processes.     

Effects of manganese on the growth,photosystem II and SOD activity of the dinoflagellate <Emphasis Type="Italic">Amphidinium</Emphasis> sp.

Experimental ecology methods and chlorophyll fluorescence technology were used to study the effects of different concentrations of manganese (10⁻¹²– 10⁻⁴ mol L⁻¹) on the growth, photosystem II and superoxide dismutase (SOD) activity of Amphidinium sp. MACC/D31. The results showed that manganese had a significant effect on the growth rate, fluorescence parameters (maximal photochemical efficiency of PSII (F _v /F _m ), photochemical quenching (qP) and non-photochemical quenching (NPQ)) in the exponential stage (days 1–3) and SOD activity of Amphidinium sp. (P < 0.05). F _v/F _m in the exponential stage in 10⁻¹² mol L⁻¹ manganese concentration was significantly lower whilst qP and NPQ significantly higher than those in the other concentrations. F _v /F _m (days 6–9) in 10⁻⁴ mol L⁻¹ manganese was significantly higher than those in the other concentrations. F _v /F _m (days 3–6) increased with increased concentration of manganese from 10⁻¹² to 10⁻⁴ mol L⁻¹. The values of qP and NPQ decreased with decreased concentrations of manganese, except for those in days 4–6. F _v /F _m under each concentration increased earlier and decreased later with culture stage whilst NPQ decreased earlier and increased later. The SOD activity increased with increased concentration of manganese from 10⁻¹² to 10⁻⁸ mol L⁻¹. The SOD activity in 10⁻⁴ mol L⁻¹ manganese was significantly higher than those in the other concentrations and in 10⁻¹² mol L⁻¹ manganese, it was significantly lower than those in the other concentrations.     

Effect of malic acid on the growth kinetics of<Emphasis Type="Italic"> Lactobacillus plantarum</Emphasis>

The fermentation kinetics of Lactobacillus plantarum were studied in a specially designed broth formulated from commercially available, dehydrated components (yeast extract, trypticase, ammonium sulfate) in batch and continuous culture. During batch growth in the absence of malic acid, the specific growth rate was 0.20 h^–1. Malic acid in the medium, at 2 mM or 10 mM, increased the specific growth rate of L. plantarum to 0.34 h^–1. An increase in the maximum cell yield due to malic acid also was observed. Malic acid in the medium (12 mM) reduced the non-growth-associated (maintenance energy) coefficient and increased the biomass yield in continuous culture, based on calculations from the Luedeking and Piret model. The biomass yield coefficient was estimated as 27.4 mg or 34.3 mg cells mmol^–1 hexose in the absence or presence of malic acid, respectively. The maintenance coefficient was estimated as 3.5 mmol or 1.5 mmol hexose mg^–1 cell h^–1 in the absence or presence of malic acid. These results clearly demonstrate the energy-sparing effect of malic acid on the growth- and non-growth-associated energy requirements for L. plantarum. The quantitative energy-sparing effect of malic acid on L. plantarum has heretofore not been reported, to our knowledge.     

Effect of traumatic acid on antioxidant activity in <Emphasis Type="Italic">Chlorella vulgaris</Emphasis> (Chlorophyceae)

The present study was undertaken to test the influence of exogenously applied traumatic acid (TA) upon the activity of several antioxidant enzymes as well as lipid and protein peroxidation in green algae Chlorella vulgaris. Treatment with TA in concentration range of 10⁻⁶–10⁻⁵ M resulted in an increase of antioxidant enzyme (sodium dismutase, catalase, ascorbate peroxidase, NADH peroxidase, glutathione reductase) activity. Moreover, TA suppressed lipid peroxidation and oxidative destruction of proteins belonging to the SH groups. This data suggest that TA plays an important role in the metabolism of C. vulgaris and probably in its high ability to adapt to various environmental stress factors.     

Determination of shelf life of <Emphasis Type="Italic">Spirulina platensis</Emphasis> (MI<Subscript>2</Subscript>) grown in the Philippines

Gamma linolenic acid (GLA) degradation in Spirulina followed first-order reaction kinetics. At an accelerated temperature range of 45 to 55°C, the degradation rate constants (k _r) of GLA obtained were 4.0 × 10⁻² to 8.8 × 10⁻² day⁻¹. The energy of activation (E _a) was 16.53 kcal mol⁻¹, and the Q₁₀ was 2.22. Based on 20% GLA degradation, the shelf life of sun-dried Spirulina at 30°C is 263 days or 8.6 months using the Arrhenius plot, and 258 days or 8.5 months using the Q ₁₀ approach. Presented at the 6th Meeting of the Asia Pacific Society of Applied Phycology, Manila, Philippines.     

Comparison of specificity and sensitivity of immunochemical and molecular techniques for determination of <Emphasis Type="Italic">Clavibacter michiganensis</Emphasis> subsp. <Emphasis Type="Italic">michiganensis</Emphasis>

Detection of Clavibacter michiganensis subsp. michiganensis (Cmm), causing bacterial canker of tomato, was verified using PTA-ELISA and IFAS with PAbs of Neogen Europe Ltd. (UK), and with published and also laboratory-generated PCR primers from the Cmm tomatinase gene. The specificity of this technique was determined with 15 plant-pathogenic and 4 common, saprophytic bacteria. With IFAS, crossreactions were found for Pantoea dispersa, P. agglomerans and Rahnella aquatilis, and with PTA-ELISA for Curtobacterium flaccumfaciens, Pectobacterium atrosepticum and Dickeya sp. Cross-reactions with subspecies other than michiganensis were also found using both methods. Molecular methods were optimized by verification of annealing temperatures and times for both primers. Conditions were finally adjusted to 30 s at 65 °C for Dreier’s and 10 s at 69 °C for our primer set. After this optimization, both primer pairs produced positive reaction only with Cmm. By means of PTA-ELISA and IFAS, Cmm strains were detected at a concentration up to 10⁵ CFU/mL and 10³ CFU/mL, respectively. The PCR test with bacterial cell suspensions reached a sensitivity of 10³ CFU/mL with our designed primers and 104 CFU/mL with Dreier’s primer pair.     

The Involvement of Calcium Transport Systems of the Plasma Membrane in Calcium Exchange in Neurons of the <Emphasis Type="Italic">Carassius gibelio</Emphasis> Cerebellum

We studied the role of Na⁺/Ca²⁺ exchanger (NCX) and Ca²⁺-ATPase of the plasma membrane (РМСА), known to be the most important intracellular systems controlling calcium exchange in cerebellar neurons of a fish species tolerant to hypoxia, Carassius gibelio. In our experiments, we used the corresponding blockers of these transport systems, ions of lithium and lanthanum. The intracellular Ca2+ concentration ([Ca²⁺] _і ) was measured using a calcium-sensitive dye, Fura-2AM, and a microfluorescence technique. We found that neurons of the Carassius cerebellum possess an effective system of cleaning of the cytoplasm from excessive Ca²⁺, which is provided by both NCX and РМСА functioning in the plasma membrane. Under conditions of the blockade of functioning of РМСА using lanthanum, the basal Ca²⁺ level in the cells increased, on average, by 31.4% with respect to the control, independently of the duration of test depolarizations. After switching off of the NCX functioning by the replacement of sodium ions in the extracellular solution by lithium ions, the Ca²⁺ level in the cell increased by 36.6% with respect to the control (also independently of the duration of depolarization). The obtained data indicate that the functioning of РМСА and NCX in Carassius cerebellar neurons significantly influences the intracellular calcium exchange providing the maintenance of an adequate basal Ca2+ level in these neurons.     

Serum testosterone in females exposed to natural sour gas with respect to polymorphisms of <Emphasis Type="Italic">XRCC1</Emphasis>, <Emphasis Type="Italic">GSTM1</Emphasis>, and <Emphasis Type="Italic">GSTT1</Emphasis>

The present study was done to determine the modulation effect(s) of polymorphisms of XRCC1, GSTM1, and GSTT1 on concentration of serum testosterone in females exposed to natural sour gas. Also we examine whether chronic exposure to natural gas containing sulfur compounds act as natural selection force on XRCC1 polymorphisms. The present study was performed on 68 healthy unrelated female students living in polluted areas of MIS. Also for investigating the effect of natural selection on XRCC1 polymorphism, a study was performed on two groups of healthy individuals of MIS citizens. The first and second groups including 94 (age range 30–85 years) and 187 individuals (age range 5–20 years), respectively. First and second groups were born and were not born in contaminated areas of the MIS, respectively. There was no significant difference between genotypes of XRCC1 for concentration of serum testosterone. Although GSTT1-null genotype had higher level of serum testosterone in comparison with the present genotype (t = 2.392, df = 66, P = 0.023), a borderline difference between genotypes of GSTM1 for serum testosterone was observed (t = 1.928, df = 66, P = 0.058). Analysis of variance revealed significant difference between combination genotypes of GSTM1 and GSTT1 for serum testosterone (F = 4.167; df = 3, 64; P = 0.009). The Duncan post hoc test indicated that the combination genotype of “present GSTM1/null GSTT1” had significant higher level of testosterone. There is no evidence that XRCC1 polymorphisms have advantage/disadvantage when population exposed to natural sour gas. The polymorphisms of GSTM1 and GSTT1 modulate serum testosterone concentration in young females exposed to natural sour gas.     

Environmentally relevant cadmium concentrations affect development and induce apoptosis of <Emphasis Type="Italic">Paracentrotus lividus</Emphasis> larvae cultured in vitro

Sea urchin embryos and larvae represent suitable model systems on where to investigate the effects of heavy metals on development and cell viability. Here, we tested the toxic effects of low (10⁻¹² M), medium (10⁻⁹ M), and high (10⁻⁶ M) cadmium chloride concentrations, mimicking unpolluted, moderately and highly polluted seawaters, respectively, on Paracentrotus lividus sea urchins offspring. Larvae were continuously treated from fertilization and inspected at time intervals comprised between 10 and 30 days of development. Delays and/or morphological abnormalities were firstly evident in larvae treated for 15 days with high cadmium (10⁻⁶ M) and for 25 days with medium cadmium (10⁻⁹ M). Major defects consisted in the reduction and lack of arms and skeleton elongation. No obvious differences with respect to controls were observed in embryos/larvae exposed to low cadmium (10⁻¹² M), even after 30 days of exposure. Using in situ terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay (TUNEL) assay on larvae whole mounts, we detected apoptosis after 10 days of treatment with 10⁻⁶ and 10⁻⁹ M CdCl_2, when no morphological abnormalities were recognizable yet. Supernumerary apoptotic cells were found in arm buds, ciliary bands, and apex. In conclusion, echinoderm embryos and larvae represent candidates of choice for the study of stress and defense mechanisms activated by cadmium exposure.     

Bioaugmentation of the decolorization rate of acid red GR by genetically engineered microorganism <Emphasis Type="Italic">Escherichia coli</Emphasis> JM109 (pGEX-AZR)

The study showed that the genetically engineered microorganism (GEM) bioaugment successfully the dye wastewater biotreatment systems to enhance acid red GR (ARGR) removal. Escherichia coli JM109 (pGEX-AZR) was the GEM with higher azoreductase activity. The kinetics of the ARGR decolorization by the E. coli JM109 (pGEX-AZR) agreed with Andrews model. The kinetic parameters, r _dye,max, K _s and K _i , were found to be 42.45 mg g⁻¹ h⁻¹, 584.93 mg L⁻¹ and 556.89 mg L⁻¹, respectively. The E. coli JM109 (pGEX-AZR) was tested in anaerobic sequencing batch reactors (AnSBR) in order to enhance the ARGR decolorization. The decolorization rate of ARGR was affected by the amount of E. coli JM109 (pGEX-AZR) inoculation and the best amount of inoculation was 10%. The continuous operations of the four bioreactors with different E. coli JM109 (pGEX-AZR) immobilization supports showed that the E. coli JM109 (pGEX-AZR) could bioaugment decolorization in AnSBRs with suspended and immobilized on macroporous foam carriers. For 42 days continuous operation in the AnSBRs, both the tolerance to ARGR concentration shock and the decolorization rate in these two bioaugmented AnSBRs are higher than those of the other two systems, control system and bioaugmented AnSBRs system with the sodium-alginate immobilized cells, the decolorization rate reached 90%. Changes in microbial community were detected by ribosomal intergenic spacer analysis (RISA) and amplified ribosomal DNA restriction analysis (ARDRA), which revealed that the introduced E. coli JM109 (pGEX-AZR) was persistent in the augmented systems and maintained higher metabolic activity.     

Dynamics of <Superscript>18</Superscript>O Incorporation from H <Subscript>2</Subscript><Superscript>18</Superscript>O into Soil Microbial DNA

Heavy water (H₂¹⁸O) has been used to label DNA of soil microorganisms in stable isotope probing experiments, yet no measurements have been reported for the ¹⁸O content of DNA from soil incubated with heavy water. Here we present the first measurements of atom% ¹⁸O for DNA extracted from soil incubated with the addition of H₂¹⁸O. Four experiments were conducted to test how the atom% ¹⁸O of DNA, extracted from Ponderosa Pine forest soil incubated with heavy water, was affected by the following variables: (1) time, (2) nutrients, (3) soil moisture, and (4) atom% ¹⁸O of added H₂O. In the time series experiment, the atom% ¹⁸O of DNA increased linearly (R ² = 0.994, p < 0.01) over the first 72 h of incubation. In the nutrient addition experiment, there was a positive correlation (R ² = 0.991, p = 0.006) between the log₁₀ of the amount of tryptic soy broth, a complex nutrient broth, added to soil and the log₁₀ of the atom% ¹⁸O of DNA. For the experiment where soil moisture was manipulated, the atom% ¹⁸O of DNA increased with higher soil moisture until soil moisture reached 30%, above which ¹⁸O enrichment of DNA declined as soils became more saturated. When the atom% ¹⁸O for H₂O added was varied, there was a positive linear relationship between the atom% ¹⁸O of the added water and the atom% ¹⁸O of the DNA. Results indicate that quantification of ¹⁸O incorporated into DNA from H₂¹⁸O has potential to be used as a proxy for microbial growth in soil.     

Evaluation of <Emphasis Type="Italic">Isochrysis galbana</Emphasis> (clone T-ISO) cell numbers by digital image analysis of color intensity

In microalgal cultivation, measuring cell numbers as a means to monitor growth rates is a long-standing problem. Many automated counting systems and schemes have been developed; among these are image analysis systems. However, such imaging systems have presented difficulties in dealing with the complexities of computer recognition of individual microscopic cells. It is known that the coloration of microalgae suspension is species specific and that color intensity increases are typically associated with increasing numbers. Using this qualitative insight, the present work describes the design, construction, and comparative performance of an inexpensive digital imaging system optimized for counting microalgal cells. The system circumvents the need to count individual cells and extracts cell numbers directly from the macroscopic color intensity of a microalgal suspension. The results suggest, using Isochrysis galbana (T-ISO) as an illustrative example, that this scheme is potentially useful for inexpensive and automated biomonitoring of microalgal cell numbers. Percentage difference comparisons with a standard Coulter Counter indicated that the three algorithms tested provided better than 10% accuracy over density thresholds of 1.52 × 10⁶ to 8.10 × 10⁶ cells mL⁻¹ with precision of 4% attainable at high density concentrations.     

Detection of living <Emphasis Type="Italic">Salmonella</Emphasis> cells using bioluminescence

ATP-based bioluminescence using mutant firefly luciferase was combined with an immunochromatographic lateral flow test strip assay for Salmonella enteritidis detection. In this combination method, the Salmonella-antibody–gold complex captured at the test line on the test strip was lysed by heat-treatment, and the ATP released from the cells was measured using mutant luciferase. This method resulted in approximately 1,000 times higher sensitivity in the detection of Salmonella (i.e. 10³ c.f.u./ml) compared to immunochromatographic lateral flow assay.     

Dietary Macrogard reduces <Emphasis Type="Italic">Aeromonas hydrophila</Emphasis> mortality in tench (<Emphasis Type="Italic">Tinca tinca</Emphasis>) through the activation of cellular and humoral defence mechanisms

Influence of beta-1.3/1.6-glucan (Macrogard) on the innate immunity and protection against Aeromonas hydrophila in tench (Tinca tinca (L.)) was assessed. Macrogard was fed at doses of 0, 0.5, 1 and 2 g kg⁻¹ of pellets for 1 month. The blood, spleen and head kidney from 10 fish of each group were separated and analysed for immunity parameters. Twenty tench from each group were infected with A. hydrophila. Macrogard at doses 1 and 2 g kg⁻¹ of feed significantly (P < 0.05) increased the phagocytic activity of macrophages and proliferative response of mitogens stimulated lymphocytes. The same doses significantly (P < 0.05) increased lysozyme activity and Ig level in serum, compared to the control and dose 0.5 g kg⁻¹ of feed. The challenge test showed that Macrogard reduced mortality of tench after experimental infection (5–35%).     

Optimization of culture conditions and scale-up to pilot and plant scales for coenzyme Q<Subscript>10</Subscript> production by <Emphasis Type="Italic">Agrobacterium tumefaciens</Emphasis>

This report describes the optimization of culture conditions for coenzyme Q₁₀ (CoQ₁₀) production by Agrobacterium tumefaciens KCCM 10413, an identified high-CoQ₁₀-producing strain (Kim et al., Korean patent. 10-0458818, 2002b). Among the conditions tested, the pH and the dissolved oxygen (DO) levels were the key factors affecting CoQ₁₀ production. When the pH and DO levels were controlled at 7.0 and 0–10%, respectively, a dry cell weight (DCW) of 48.4 g l⁻¹ and a CoQ₁₀ production of 320 mg l⁻¹ were obtained after 96 h of batch culture, corresponding to a specific CoQ₁₀ content of 6.61 mg g-DCW⁻¹. In a fed-batch culture of sucrose, the DCW, specific CoQ₁₀ content, and CoQ₁₀ production increased to 53.6 g l⁻¹, 8.54 mg g-DCW⁻¹, and 458 mg l⁻¹, respectively. CoQ₁₀ production was scaled up from a laboratory scale (5-l fermentor) to a pilot scale (300 l) and a plant scale (5,000 l) using the impeller tip velocity (V _tip) as a scale-up parameter. CoQ₁₀ production at the laboratory scale was similar to those at the pilot and plant scales. This is the first report of pilot- and plant-scale productions of CoQ₁₀ in A. tumefaciens.     

The effect of indomethacin on the growth and metabolism of green alga <Emphasis Type="Italic">Chlorella vulgaris</Emphasis> Beijerinck

The aim of the present work was to study the effect of indomethacin (IM), a pleiotropic therapeutic substance commonly used in animal systems, at concentration range of 10⁻⁸ to 10⁻³ M on the growth and metabolism of single-celled Chlorella vulgaris (Chlorophyceae). Because of the presence of the indole ring in its molecule, IM is characterized by structural similarity with natural auxins, e.g. IAA. It was found that IM influenced algal growth, macromolecular synthesis and metabolism in dose-dependent manner. IM had the highest stimulating effect on algae at 10⁻⁷ M on the 5th day of culture resulting in the increase in cell number and dry mass, DNA, RNA, proteins, phosphates, monosaccharides, photosynthetic pigments and glycolic acid content as well as protein extracellular secretion to the environment. Specific proteins from the region 20–139 kDa appeared during 10⁻⁷ M IM treatment on the 5th day of cultivation as analysed by SDS-PAGE. IM-induced photosynthetic oxygen exchange in green alga was also noted. In contrast, the treatment with IM at the highest concentration of 10⁻³ M suppressed cell division, dry mass production and decreased the level of the analysed parameters during the whole 7-day period of cultivation. Therefore, it could be speculated that IM functioned as a plant growth regulator affecting cell division and metabolism of green alga C. vulgaris.     

Kinetics of Phase Separation of Oat β-Glucan/Whey Protein Isolate Binary Mixtures

The kinetics of phase separation and microstructure of oat β-glucan/whey protein binary mixtures varying in concentration (4–16% w/v protein, 0.3–1.2% w/v β-glucan) and β-glucan molecular weight (1.3 × 10⁶, 640 × 10³, 180 × 10³, and 120 × 10³ g/mol) was investigated by turbidimetry and fluorescent microscopy. The phase separation of the mixed systems was followed at pH 7.0 and at room temperature under quiescent conditions. Application of first principles revealed that phase separation of the systems follows first-order kinetics. Acceleration of the phase-separation process was observed with increase of β-glucan concentration for the three lowest-MW samples but the highest molecular weight (1.3 × 10⁶ g/mol) exhibited the opposite trend. Changes in the polysaccharide molecular weight resulted in considerable differences in β-glucan aggregate morphology in the mixed systems. The change in the continuity of the mixed system from polysaccharide-, to bi-, to protein-continuous was confirmed for a wide range of mixed systems differing in biopolymer concentration, and β-glucan molecular weight.