Seafood Processing Plants Research Articles

Quality Determinants of Gillnet-Caught Alaska Salmon

ABSTRACTIn 2010 and 2011, researchers in Bristol Bay, Alaska followed nearly 22,000 tagged sockeye salmon that were caught by 86 selected gillnet boats and delivered unfrozen to tenders anchored out on the fishing grounds. The fish were then chilled in refrigerated seawater (RSW) and transported, usually within 24 h, to a shore-based seafood processing plant, where they were graded using a sensory evaluation method. Handling practices on the fishing boats were documented, along with the distance from the fishing grounds to the processing plant. Fishermen who employed RSW chilling tended to deliver higher quality salmon than fishermen chilling with ice. Fish that were bled at time of harvest and fish that were shaken from the gillnet onto a rubber mat or “salmon slide” were generally of slightly higher quality than fish that were not bled and were dropped onto a hard deck.

Longitudinal monitoring of Listeria monocytogenes and Listeria phages in seafood processing environments in Thailand

Listeria monocytogenes is a foodborne pathogen commonly found in environments of seafood processing, thus presenting a challenge for eradication from seafood processing facilities. Monitoring the prevalence and subtype diversity of L. monocytogenes together with phages that are specific to Listeria spp. (“Listeria phages”) will provide knowledge on the bacteria-phage ecology in food processing plants. In this work, a total of 595 samples were collected from raw material, finished seafood products and environmental samples from different sites of a seafood processing plant during 17 sampling visits in 1.5 years of study. L. monocytogenes and Listeria spp. (non-monocytogenes) were found in 22 (3.7%) and 43 (7.2%) samples, respectively, whereas 29 Listeria phages were isolated from 9 (1.5%) phage-positive samples. DNA fingerprint analysis of L. monocytogenes isolates revealed 11 Random Amplified Polymorphic DNA (RAPD) profiles, with two subtypes were frequently observed over time. Our data reveal a presence of Listeria phages within the same seafood processing environments where a diverse set of L. monocytogenes subtypes was also found. Although serotype 4b was observed at lower frequency, data indicate that isolates from this seafood processing plant belonged to both epidemiologically important serotypes 1/2a and 4b, which may suggest a potential public health risk. Phages (all showed a unique genome size of 65 ± 2 kb) were classified into 9 host range groups, representing both broad- and narrow-host range. While most L. monocytogenes isolates from this facility were susceptible to phages, five isolates showed resistance to 12–20 phages. Variations in phage host range among Listeria phages isolated from food processing plant may affect a presence of a diverse set of L. monocytogenes isolates derived from the same processing environment in Thailand.

Spectroscopic analysis of heavy metal in frozen shrimp from different seafood processing plants of Chittagong, Bangladesh

This study is carried out to determine the level of three common heavy metals i.e. mercury (Hg), lead (Pb) and cadmium (Cd) from different branded frozen shrimp samples from different processing plants in Chittagong Metropolitan Area, Bangladesh. The level of heavy metals is investigated by using Atomic Absorption Spectrophotometer (AAS) in twenty different frozen shrimp samples from four different processing plants. The range of mean level of concentration (mg/kg) of mercury (Hg), lead (Pb) and cadmium (Cd) are 0.011-0.042 mg/kg, 0.065-0.087 mg/kg and 0.024-0.081 mg/kg respectively. Lead (Pb) has the highest mean concentration of 0.087 mg/kg while mercury has the lowest mean of 0.011 mg/kg. The mean concentration of mercury (Hg), lead (Pb) and cadmium (Cd) in shrimps was observed within the range of BSTI (Bangladesh Standards and Testing Institution) standards for aquatic foods.Asian J. Med. Biol. Res. December 2016, 2(4): 513-517

Physicochemical characterization of Atlantic Canadian seafood processing plant effluent

The purpose of this study was to conduct a preliminary assessment of the potential impacts of Atlantic Canadian seafood processing effluents on the aquatic environment through physical-chemical characterization. Shellfish and finfish effluent samples were collected and characterized by biochemical oxygen demand (BOD5), chemical oxygen demand (COD), turbidity, total suspended solids (TSS), ammonia nitrogen (NH3-N), adsorbable organic halides (AOX), soluble BOD5 and soluble COD. Effluent concentration ranges were BOD5 (179 to 276mgL−1), COD (458 to 1717mgL−1), turbidity (28.8 to 88.3NTU), TSS (27.2 to 120.1mgL−1), NH3-N (1.5 to 12.9mgL−1) and AOX (3.2 and 0.4mgL−1) for flatfish and salmon processing effluents respectively, and cleanup shift AOX (3.5 and 0.5mgL−1). The characteristics of these effluents assessed have the potential to contaminate and degrade receiving water body environments. Improved performance may be possible with further treatment technology optimization on an effluent-specific basis.

Seafood-Processing Sludge Composting: Changes to Microbial Communities and Physico-Chemical Parameters of Static Treatment versus for Turning during the Maturation Stage.

In general, in composting facilities the active, or intensive, stage of the process is done separately from the maturation stage, using a specific technology and time. The pre-composted material to be matured can contain enough biodegradable substrates to cause microbial proliferation, which in turn can cause temperatures to increase. Therefore, not controlling the maturation period during waste management at an industrial level can result in undesired outcomes. The main hypothesis of this study is that controlling the maturation stage through turning provides one with an optimized process when compared to the static approach. The waste used was sludge from a seafood-processing plant, mixed with shredded wood (1:2, v/v). The composting system consists of an intensive stage in a 600L static reactor, followed by maturation in triplicate in 200L boxes for 112 days. Two tests were carried out with the same process in reactor and different treatments in boxes: static maturation and turning during maturation when the temperature went above 55°C. PLFAs, organic matter, pH, electrical conductivity, forms of nitrogen and carbon, hydrolytic enzymes and respiratory activity were periodically measured. Turning significantly increased the duration of the thermophilic phase and consequently increased the organic-matter degradation. PCA differentiated significantly the two treatments in function of tracking parameters, especially pH, total carbon, forms of nitrogen and C/N ratio. So, stability and maturity optimum values for compost were achieved in less time with turnings. Whereas turning resulted in microbial-group stabilization and a low mono/sat ratio, static treatment produced greater variability in microbial groups and a high mono/sat ratio, the presence of more degradable substrates causes changes in microbial communities and their study during maturation gives an approach of the state of organic-matter degradation. Obtaining quality compost and optimizing the composting process requires using turning as a control mechanism during maturation.

Prevalence of Salmonella and Escherichia coli contamination in shrimp (Penaeus monodon) farms, depots and processing plants in different areas of Bangladesh

A study was conducted to determine the level of contamination by indicator organisms (Salmonella and Escherichia coli) in shrimp (Penaeus monodon) farms, depots and processing plants of Cox’s Bazar, Khulna, Bagerhat and Satkhira districts of Bangladesh using conventional technique of bacterial isolation and identification. The results of this study revealed that prevalence of Salmonella positive samples was 43.7%, 62.5%, 20% and 0.0% for water, pond scum, shrimp and basket samples, respectively at farm level. Meanwhile, the prevalence of E. coli positive samples was 62.5%, 43.7%, 60% and 60% for water, pond scum, shrimp and basket samples, respectively at farm level. In case of depots, shrimp, basket and mat samples were analyzed and found 20%, 56.3% and 23% positive for Salmonella and 53.3%, 37.5% and 92.3% positive for E. coli. Bacteriological assessment of the shrimp samples obtained from four seafood processing plants revealed that all the samples were found contaminated with Salmonella and E. coli except the samples of one industry. Investigation finally showed that with few exceptions all the samples from farms, depots and processing plants have different levels of contamination by Salmonella and E. coli, which is very much alarming for shrimp industry of Bangladesh.Asian J. Med. Biol. Res. June 2016, 2(2): 171-176

Prevalence and molecular characterization of Listeria spp. and Listeria monocytogenes isolated from fish, shrimp, and cooked ready-to-eat (RTE) aquatic products in Iran

The prevalence of Listeria spp. and Listeria monocytogenes was investigated by biochemical and molecular methods in a total of 201 fish, shrimp, and ready-to-eat seafood samples collected from Iranian supermarkets. Thirty-six samples were also collected from a seafood processing plant. Twenty-one (8.86%) of the total retail and processing plant samples (237) were positive for Listeria spp., confirmed by a simplex PCR assay for the prs gene. Seven (2.95%) of the total samples were also positive for L. monocytogenes. The presence of four virulence-associated genes in the seafood isolates (inlA, inlC, inlJ, and hlyA) was examined using PCR and the results were compared with seven clinical L. monocytogenes strains. All virulence genes were detected in six fish isolates. One fish isolate did not show amplification of the inlJ and inlC genes. However, all seven clinical strains were positive for internalin genes. Furthermore, a multiplex PCR assay was employed to evaluate the major L. monocytogenes genoserogroups’ distribution. The results revealed that the serotypes of lineage II are most frequently present in clinical and food isolates. In summary, PCR screening for both the major L. monocytogenes serovars and virulence genes revealed the potential public health risk posed by L. monocytogenes in aquatic products.

Nutrigenomics study in atlantic salmon (Salmo salar) fed novel diets supplemented with marine by-products

The processing of seafood for human or animal consumption creates vast amounts of by-product, which is often considered waste. Although some of these by-products are used as fishmeal, bone-meal or fertilizer, they remain underutilized as a whole. Significant amounts of proteins, lipid fractions, vitamins, and other bioactive molecules are present in these by-products, with potentially beneficial properties for use as alternatives to fishmeal or as supplements for aquaculture species. In an attempt to investigate their potential benefit in Atlantic salmon fish nutrition, nine experimental diets were formulated to include marine by-products originating from various seafood processing plants. Juvenile Atlantic salmons were fed one of the nine experimental diets (30% marine by-product, 70% basal diet) or the basal diet alone. Hepatic gene expression profiling was done on fish fed each diet after 14 and 56 days. Analysis of hepatic gene expression revealed a significant amount of differentially expressed genes for each diet with roles in various pathways and biological processes. By comparing differences in hepatic gene expression levels with the nutritional composition of the various feeds, we were able to identify a number of nutritional elements that affect specific gene families. This information will be very useful for the formulation of novel fish feeds, which may be designed with specific aims, such as rapid growth, increased immunity or better overall health. .

Biofilm formation of the L. monocytogenes strain 15G01 is influenced by changes in environmental conditions

Listeria monocytogenes 15G01, a strain belonging to the persistent pulsotype 5132, was isolated from a seafood processing plant in New Zealand. Simple monoculture assays using crystal violet staining showed good biofilm formation for this strain and it was therefore chosen to be further investigated in regard to its biofilm forming ability. To evaluate its behaviour in different conditions commonly encountered in food processing environments, biofilm assays and growth studies were performed using common laboratory media under a range of temperatures (20°C, 30°C and 37°C). Furthermore, the effects of incubation time and different environmental conditions including static, dynamic and anaerobic incubation on biofilm formation were investigated. Changes in the environmental conditions resulted in different biofilm phenotypes of L. monocytogenes 15G01. We demonstrated that increasing temperature and incubation time led to a higher biofilm mass and that dynamic incubation has little effect on biofilm formation at 37°C but encourages biofilm formation at 30°C. Biofilm production at 20°C was minimal regardless of the medium used. We furthermore observed that anaerobic environment led to reduced biofilm mass at 30°C for all tested media but not at 37°C. Biofilm formation could not be narrowed down to one factor but was rather dependent on multiple factors with temperature and medium having the biggest effects.

Adhesive Microflora on Stainless Steel Coupons in Seafood Processing Plant

Adhering microflora profile is essential for the development and design of cleaning and sanitizing procedures, which is a part of the HACCP system. The profile provides a complete view of the target microorganisms that can potentially contaminate food products. The aim of this study is, therefore, focused on examination of microbial population adhered to the equipment surfaces at seafood processing plant. Adhering microflora was evaluated by installing the stainless steel coupons on the surface of equipment. Seventy stainless steel coupons were attached on 7 different locations at seafood processing plant and then fourteen coupons were collected at 1, 2, 3, 5 and 9 weeks interval. The population of bacteria adhered on samples were enumerated using swab test and spread plate method on different selective microbiological media. The total viable count and Pseudomonas spp. population found on the stainless steel coupons were ranged from 101 to 106cfu/cm2. The results also indicated that mature biofilm might form at some locations after three weeks. After 5 weeks, the highest viable bacterial population (106cfu/cm2) was observed on the stainless steel coupons attached in the trolley used for carrying the soup. These finding supported that the appropriate cleaning and sanitizing procedure should be strictly applied to assure safety in food processing plant.

Occurrence and diversity of Listeria spp. in seafood processing plant environments

Listeria contamination in processing plant environments is a major issue for the seafood industry worldwide; faster and more reliable results are therefore desired for early detection and monitoring of environmental Listeria spp. This study aimed to gain a better understanding of the prevalence and diversity of Listeria spp., and to evaluate a rapid detection method, the 3M Molecular Detection Assay (MDA) Listeria, for its ability to detect Listeria spp. in environmental samples from seafood processing plants. Duplicate environmental sponge samples (n = 444) were collected from 152 different sites within three seafood processing plants, and analyzed for Listeria spp. by the MDA method (after 26 and 48 h of enrichment) and the U.S. Food and Drug Administration Bacteriological Analytical Manual method. Overall, detection of Listeria spp. by the two methods did not differ significantly (p > 0.05); 11 (4.9%) and 13 (5.9%) samples were positive for Listeria spp. by the MDA and FDA-BAM method, respectively. The sensitivity of the MDS was 87.0% (95% CI: 77.4–96.6%), specificity was 97.6% (95% CI: 95.5–99.7%), accuracy was 95.3%, and the positive predictive value was 89.4% (95% CI: 80.5–98.2%). Classification of 19 Listeria isolates by partial SigB sequencing analysis identified three allelic types. Twelve of these isolates were ATs 58 and 60 which were classified as Listeria monocytogenes lineage I and serotypes 1/2b, 3b, 4b, 4d, 4e, by multiplex-PCR serotyping. Six Listeria isolates were classified as Listeria innocua (AT31). Our data show that the 3M Molecular Detection Assay Listeria provides rapid and reliable results for detection and monitoring of Listeria spp., which are important for seafood processing plants. Effective Listeria monitoring programs will allow for improved development of Listeria control measures in order to minimize cross-contamination in finished products.

Isolation and structural characterisation of acid- and pepsin-soluble collagen from the skin of squid Sepioteuthis lessoniana (Lesson, 1830)

Acid-solubilised collagen (ASC) and pepsin-solubilised collagen (PSC) were effectively isolated from squid skin with good yield and total protein content. ASC and PSC consist of two α-chains with an imino acid content of 182.6 and 184 imino acid residues/1000 residues. The molecular weight was determined to be between 73 and 107 kDa by using SDS-PAGE. For peptide mapping, collagens were digested with achromo endopeptidase, and all components, including α, β-chains, were markedly hydrolysed. Degradation peptides with molecular weights between 106.9 and 15.47 kDa were obtained. UV–vis absorption spectrum revealed distinct absorption at 220–240 nm. FT-IR spectra of collagens were almost similar when compared with standard. In differential scanning calorimetry profile, ASC and PSC exhibited a To of 59.10, 62.18°C and TP of 104.91, 98.10 °C, respectively. This investigation indicates that the collagen isolated from the squid skin, which is thrown as waste in the seafood-processing plant, might supplement the vertebrate collagen in industrial applications.

Listeria monocytogenes Associated with New Zealand Seafood Production and Clinical Cases: Unique Sequence Types, Truncated InlA, and Attenuated Invasiveness

Listeriosis is caused by the food-borne pathogen Listeria monocytogenes, which can be found in seafood and processing plants. To evaluate the risk to human health associated with seafood production in New Zealand, multi-virulence-locus sequence typing (MVLST) was used to define the sequence types (STs) of 31 L. monocytogenes isolates collected from seafood-processing plants, 15 from processed foods, and 6 from human listeriosis cases. The STs of these isolates were then compared with those from a collection of seafood isolates and epidemic strains from overseas. A total of 17 STs from New Zealand clustered into two lineages: seafood-related isolates in lineages I and II and all human isolates in lineage II. None of the New Zealand STs matched previously described STs from other countries. Isolates (belonging to ST01-N and ST03-N) from mussels and their processing environments, however, were identical to those of sporadic listeriosis cases in New Zealand. ST03-N isolates (16 from mussel-processing environments, 2 from humans, and 1 from a mussel) contained an inlA premature stop codon (PMSC) mutation. Therefore, the levels of invasiveness of 22 isolates from ST03-N and the three other common STs were compared using human intestinal epithelial Caco-2 cell lines. STs carrying inlA PMSCs, including ST03-N isolates associated with clinical cases, had a low invasion phenotype. The close relatedness of some clinical and environmental strains, as revealed by identical MVLST profiles, suggests that local and persistent environmental strains in seafood-processing environments pose a potential health risk. Furthermore, a PMSC in inlA does not appear to give L. monocytogenes a noninvasive profile.

Evaluation of nitrogen sources in the Urias lagoon system, Gulf of California, based on stable isotopes in macroalgae

The concentrations of chemical forms of nitrogen (N) and their isotopic composition in the water column and the δ15N signals in 738 samples of macroalgae collected during one year across the Urías lagoon system (Mazatlán, Sinaloa, Mexico) were analyzed in order to study the N sources. The δ15N-macroalgae premise is that they register and integrate the variability of N and may provide time-integrated information about N pollution. To validate this premise, we applied two models to predict the isotopic variability of N available in the water column (δ15N-DIN): one is based on a physical mixing balance of N sources (simple model), and the second includes the effects of the biogeochemical processes on the signals (coupled model, CM). Both models showed significant R2, but CM better explained the δ15N-DIN variability. The relation between δ15N-DINCM and δ15N-macroalgae also showed a good fit, although lower than expected and with higher dispersion. The multiple N sources and co-occurring biogeochemical reactions, which produce a mixture of chemical species of N and of their isotopic compositions, as well as the high diversity of species (45) explained the elevated variability and lack of fit. Even so, δ15N in macroalgae is the most useful available tool to quantify the relative contributions of N to ecosystems from different sources. Based on Bayesian isotopic mixing models, the main anthropogenic sources of N to the Urías lagoonal system were domestic effluents (50%), atmospheric deposition (24%), and seafood processing plant effluents (21%), and to a lesser extent, aquaculture effluents (3%), agriculture runoff (1%), and oceanic N (1%).

Evaluation of treatment options for Atlantic Canadian seafood processing plant effluent

The purpose of this study was to evaluate different effluent treatment options for Atlantic Canadian seafood processing plants. Bench-scale testing with a 25-mesh screen, sedimentation (SED), and dissolved air flotation (DAF) was conducted. Treatment by SED and DAF was successful in reducing contaminant concentrations with maximum observed percent reductions: biochemical oxygen demand, BOD5 (90%); chemical oxygen demand, COD (60%); turbidity (99%); total suspended solids, TSS (95%); and ammonia nitrogen, NH3-N (50%). Bench-scale 25-mesh screen runs for select effluent types showed poor reduction efficiencies and appeared to provide inadequate removal of contaminants. Sedimentation and DAF using alum were effective at removing solids but less effective at removing soluble effluent components. Improved performance may be possible with further treatment technology optimization on an effluent specific basis.

Ergonomic risks in fish processing workers in Atlantic Canada

Background: The aquaculture industry is growing in Canada and is particularly strong in Atlantic Canada. Workers in the fish processing industry are required to complete a variety of tasks in a typical day and there is concern for musculoskeletal disorder. Objective: The purpose of this study was to examine the daily operations of fish processing workers to determine any musculoskeletal concerns. Methods: The ergonomic assessment consisted of several plant visits to observe the processing line and the requirements of the workers. Video recordings were made of each stage of the assembly lines. The video data was analyzed to determine high-risk jobs and to identify areas of concern. Cumulative loading was assessed using posture matching software and the video data. A Job Strain Index (JSI), Rapid Upper Limb Assessment (RULA) and the revised NIOSH lifting equation were used to identify high-risk tasks. Results: The data showed that six tasks were considered high risk; sorting fish, removal of fish bones, trimming of fish, pallet loading/conveyor operation, fish processing and cleaning of the trim machine. In addition, four categories of occupational health and safety (OHS) hazard concerns were identified (physical, chemical, biological, and psychosocial). Each category was then broken into their causative agents and potential health effects on the worker. Conclusions: Several areas for improvement were identified at this seafood processing plant. Six jobs were identified as high risk and in need of intervention. Changes in pace of work, workstation height, and new equipment would also help reduce the number of musculoskeletal injuries. The issue of job rotation should also be examined to determine its impact on musculoskeletal health. Implementation of strategies to reduce musculoskeletal disorders will help to improve the health of these workers.

Relationship between Listeria monocytogenes and Listeria spp. in Seafood Processing Plants

The objective of this study was to evaluate the relationship between prevalence of Listeria monocytogenes as an outcome and Listeria spp. as an explanatory variable by food products, food contact surfaces, and nonfood contact surfaces in seafood processing plants by using peer-reviewed published data. Nine sets of prevalence data of L. monocytogenes and Listeria spp. were collected from published studies and used for the analyses. Based on our analysis, the relationship between L. monocytogenes prevalence and Listeria spp. prevalence in food products (incoming raw materials and finish products) was significant (P = 0.04) with (low) R² = 0.36. Furthermore, Listeria spp. were not a good indicator for L. monocytogenes when testing food contact surfaces (R² = 0.10). Listeria spp. were a good indicator for L. monocytogenes only on nonfood contact surfaces (R² = 0.90). On the other hand, the presence of Listeria spp. on food contact surfaces (R² = 0.002) and nonfood contact surfaces (R² = 0.03) was not a good indicator for L. monocytogenes presence in food products. In general, prevalence of Listeria spp. does not seem to be a good indicator for L. monocytogenes prevalence in seafood processing plants.

Study Of Labour Legislation And Its Implementation To Women Workers In The Fisheries Industries Of Pakistan

Pakistan is endowed with rich fishery potential and can contribute extensively in the Nation Economy in terms of foreign exchange. At present, there is 300,000 and 400,000 employment opportunities as direct and indirect respectively. About 10,000 Fisher Women are working in different sea food Processing Plants and “Warrahs” (unregistered Processing Plants being run by the Contractors). These Fisher Women working in the “Warrahs” have been deprived off the basic fundamental rights of an Industrial Worker. This discrimination is because the fisher workers being women, resulting in appalling work conditions, low wages, insecurity of job and all types of malpractices are inflicted upon them. All these malpractices are drastically causing health problems and low productivity of fisher women thereby increasing poverty in the society.

Efficacy of electrolyzed oxidizing water against Listeria monocytogenes and Morganella morganii on conveyor belt and raw fish surfaces

Listeria monocytogenes and Morganella morganii have been implicated in listeriosis outbreaks and histamine fish poisoning, respectively. Possible sources of contamination of food products include processing equipment, food handlers, and fish smokehouses. Treatment of food preparation surfaces and of whole fish during handling with agents such as, electrolyzed oxidizing (EO) water, could reduce biofilm formation on seafood products and in seafood processing plants. We examined the efficacy of EO water against L. monocytogenes and M. morganii biofilms using the MBEC™ Assay System (Innovotech Inc.), conveyor belt coupons, and raw fish surfaces. The MBEC™ Assay System was used to assess the activity of EO water against 24-h biofilms of 90 L. monocytogenes strains and five M. morganii strains. Biofilms were exposed to PBS or EO water for 0 (control), 5, 15, and 30 min. All bacterial isolates were susceptible (reduction of 7 log10CFU) to treatment with EO water for 5 min based on results obtained using this assay system. EO water was used to treat four L. monocytogenes strains and one M. morganii strain attached to conveyor belt coupons and fish surfaces. Three L. monocytogenes strains and one M. morganii strain on belt coupons were reduced by 1–2.5 log10CFU/cm2 by exposure (5 min) to EO water compared to exposure to sterile distilled water. Strain to strain variability in susceptibility to EO water was evidenced by the fact that numbers of one L. monocytogenes strain were not reduced by EO water treatment of belt surfaces. EO water was not effective against L. monocytogenes and M. morganii on fish surfaces as growth occurred during cold storage. These results suggest that exposure of conveyor belts to EO water for a minimum of 5 min could assist in the removal of some biofilms. Removal of food residue with continuous or intermittent spraying of food processing equipment (e.g., conveyor belts, slicers) could reduce or prevent further biofilm formation. Additional sanitizers must be investigated for activity against bacteria associated with raw fish.

Mixed culture of oleaginous yeast Rhodotorula glutinis and microalga Chlorella vulgaris for lipid production from industrial wastes and its use as biodiesel feedstock

A mixed culture of oleaginous yeast Rhodotorula glutinis and microalga Chlorella vulgaris was performed to enhance lipid production from industrial wastes. These included effluent from seafood processing plant and molasses from sugar cane plant. In the mixed culture, the yeast grew faster and the lipid production was higher than that in the pure cultures. This could be because microalga acted as an oxygen generator for yeast, while yeast provided CO(2) to microalga and both carried out the production of lipids. The optimal conditions for lipid production by the mixed culture were as follows: ratio of yeast to microalga at 1:1; initial pH at 5.0; molasses concentration at 1%; shaking speed at 200 rpm; and light intensity at 5.0 klux under 16:8 hours light and dark cycles. Under these conditions, the highest biomass of 4.63±0.15 g/L and lipid production of 2.88±0.16 g/L were obtained after five days of cultivation. In addition, the plant oil-like fatty acid composition of yeast and microalgal lipids suggested their high potential for use as biodiesel feedstock.