Characterisation of malolactic conversion by Oenococcus oeni to reduce the acidity of apple juice

The high concentration of malic acid is responsible for the acidity and sourness in apple juice. Bio‐conversion of malic acid to lactic acid through malolactic conversion (MC) in apple juice using Oenococcus oeni was investigated. When apple juice was inoculated with O. oeni (1 × 10⁶ CFU mL^?1), over 90% of malic acid was converted into lactic acid within 96 h at room temperature. When pH of apple juice was adjusted to 4.1 prior to inoculation, MC was completed within 60 h. MC was enhanced at a higher temperature (30°C) when compared with room temperature. The rate of MC was directly proportional to the number of bacteria added and MC was completed within 24 h at 1 × 10⁹ CFU mL^?1 initial cell density. MC occurred equally under aerobic and anaerobic conditions. The sensory analysis of partial MC‐applied juice when compared against control revealed potential for use of MC for manufacture of low‐acid apple juice.     

Use of spent brewer's yeast in L‐(+) lactic acid fermentation

The application of by‐products from the brewing industry in lactic acid (LA) production was investigated in order to replace expensive nitrogen sources (such as yeast extract) with cheaper and renewable nitrogenous materials such as brewer's yeast (BY). In this study, brewer's spent grain (BSG) hydrolysate was used for L‐(+)‐LA fermentation by Lactobacillus rhamnosus ATCC 7469. The effect of pH control during the fermentation and the addition of various BY contents (5–50 g/L) in BSG hydrolysate on fermentation parameters was evaluated. BY addition significantly increased free amino nitrogen (FAN) concentration (by 25.2% at 5 g/L to 616% at 50 g/L). A strong positive correlation between FAN concentration in the hydrolysate and concentration of L‐(+)‐LA produced was observed (correlation coefficient of 0.913). A high cell viability of L. rhamnosus ATCC 7469 (1.95–3.32 × 10⁹ CFU/mL at the end of fermentation) was achieved in all fermentations with the addition of brewer's yeast. The addition of BY increased L‐(+)‐lactic acid yield and volumetric productivity up to 8.4% (5 g/L) and 48.3% (50 g/L). The highest L‐(+)‐LA yield (89%) and volumetric productivity (0.89 g/L h^?1) were achieved in fermentation of BSG hydrolysate with 50 g/L of BY. © 2019 The Institute of Brewing & Distilling     

Integral utilisation of barley husk for the production of food additives

A new and effective chemical–biotechnological process for the global utilisation of barley husk (obtained from the spent grains in the brewing process) is reported. With the proposed process the three main components of the lignocellulosic residue (cellulose, hemicellulose and lignin) are utilised. A first treatment with sulfuric acid (pre‐hydrolysis) allowed the solubilisation of hemicelluloses to give xylose and glucose‐containing liquors (suitable to make fermentation media for the continuous lactic acid (LA) production with L. pentosus) and a solid phase containing cellulose and lignin. In this set of experiments, a maximum volumetric productivity (Q_P) = 2.077 g L^?1 h^?1 and product yield (Y_P/S) = 0.62 g g^?1 were obtained for a dilution rate of 0.01 h^?1. The solid residues from pre‐hydrolysis were treated with NaOH in order to increase their cellulase digestibility, and dissolve the lignin content. The cellulose residue was used as substrates for lactic acid production by simultaneous saccharification and fermentation (SSF) in media containing Trichoderma reesei cellulases and Lactobacillus rhamnosus cells using the complete MRS broth or a cheaper medium. In both cases similar LA concentrations and volumetric productivities were achieved (P = 73.4–71.0 g L^?1 and Q_P = 1.28–1.25 g L^?1 h^?1, respectively), where P is LA concentration. The lignin solution obtained after the alkaline treatment was extracted with ethyl acetate in order to obtain the phenolic components. The extract obtained at pH 3 showed three times more antioxidant activity than the one extracted at pH 12.8, with an EC₅₀ of 1.396 g L^?1 for pH 3 and 4.604 g L^?1 for pH 12.8. The best extracts showed twice antioxidant activity than BHT. Copyright © 2007 Society of Chemical Industry     

Spray‐drying of pomegranate juice with prebiotic dietary fibre

The prebiotic fibres, resistant dextrin and fructooligosaccharides (FOS), were studied for use as drying‐aid agents for the spray‐drying of concentrated pomegranate juice, a low‐caloric juice containing interesting health‐related compounds. Resistant dextrin was the best drying‐aid agent as only 0.5 g g_CPJ^?1 of resistant dextrin was needed to avoid powder stickiness, compared with 1 g g_CPJ^?1 of maltodextrins and 1.5 g g_CPJ^?1 of fructooligosaccharides. The best conditions for spray‐drying a concentrated pomegranate juice (62.6% dry matter) using the resistant dextrin (NUTRIOSE) were 1.25 g_NUTRIOSE g_CPJ^?1 and 0.10 g_CPJ g_solution^?1, a liquid feed rate of 1.08 L h^?1 and an air temperature of 160 °C. Powders were easily solubilised in water, while storage at 25 °C maintained the pomegranate bioactive components, and there were no stickiness problems for at least 2 months. Resistant dextrin could be used with all kind of fruit juices in substitution of maltodextrins, and the resulting prebiotic powders could be employed for formulating novel functional foods.     

Lactobacillus salivarius for Conversion of Soy Molasses into Lactic Acid

The feasibility of conversion of soy molasses, a low value by-product of soy protein production, to lactic acid by fermentation with Lactobacillus salivarius was investigated. The basic environmental parameters affecting growth and lactic acid production were determined. Lactic acid production in soy molasses was optimal at pH 5.6 and 42°C. Addition of 0.5% yeast extract to soy molasses reduced fermentation time from 36 to 10 hr and increased lactic acid production by 30%.     

Variation in short chain fatty acid and ethanol concentration resulting from the natural fermentation of wheat and barley for inclusion in liquid diets for pigs

Fifty‐six samples of wheat and 44 samples of barley were taken, at harvest, from locations across the UK. Lactic acid bacteria (LAB) and yeasts were enumerated before the samples were ground. Following grinding, triplicate 30‐g samples of each cereal were mixed with sterile distilled water and incubated at 30, 35 or 40 °C. Samples were taken immediately after mixing and at 24‐h intervals for analysis of short‐chain fatty acids (SCFA) and ethanol by isocratic ion‐exclusion liquid chromatography. The number of LAB and yeasts present in samples ranged from 0 to 5.0 (mean 2.25 ± 1.31) and 3.30 to 6.25 (mean 4.96 ± 0.74) log₁₀ colony‐forming units (cfu) ml^?1 respectively. At 30 °C the mean concentrations (mmol l^?1) of SCFAs and ethanol were, lactic acid 59.6 ± 40.0 (range 0.14–134.9), acetic acid 23.2 ± 11.1 (range 2.9–51.4), butyric acid 17.2 ± 16.8 (range 0.0–62.2) and ethanol 15.0 ± 9.0 (range 4.6–53.7) respectively. After fermentation for 24 h only 9 of 300 fermentations produced more than 75 mmol l^?1 lactic acid, which has previously been demonstrated to prevent the growth of Salmonella in liquid pig feed. Fermenting at 35 or 40 °C had no effect on lactic acid concentration but significantly (p < 0.001) increased the concentrations of acetic and butyric acids and ethanol. These results indicate that natural fermentation cannot be relied upon to produce levels of SCFAs that will prevent the proliferation of enteropathogens. Copyright © 2004 Society of Chemical Industry     

Malolactic fermentation in sea buckthorn (Hippophaë rhamnoides L.) juice processing

Malolactic fermentation (MLF) traditionally used in winemaking was applied to sea buckthorn to reduce the high sourness of the berry juice. Chemical and microbiological aspects, as well as sensory properties of the juice during MLF were studied in order to develop an optimal process. In 1:1 water diluted juice with malic acid content of 15 g/l and pH 2.8, efficient conversion of l-malic acid to l-lactic acid was achieved with direct inoculation of unadapted Oenococcus oeni at a cell density of 10⁹ CFU/ml. The rapid malic acid degradation was performed by non-growing bacterial cells without loss of sugars, vitamin C, or pulp oil. More than 50% of the initial malic acid was metabolized to lactic acid and CO₂ already in 12 h of fermentation and a significant decrease in sourness and astringency was noticed. In 24 h fermentation, pH value was increased to 3.1 and only 3 g/l malic acid remained in the juice. Prolonged fermentation had only minor effect on malolactic reaction, but off-flavor of the juice began to increase.     

Sensorically and antimicrobially active metabolite production of Lactobacillus strains on Jerusalem artichoke juice

BACKGROUND: In the tubers of Jerusalem artichoke (Helianthus tuberosus L.) the main carbohydrate is the well‐known prebiotic inulin, which is a good growth substrate for gut microorganisms. Jerusalem artichoke tuber is traditionally consumed boiled or pickled rather than in fermented form. Lactic acid bacteria are traditionally used in the production of fermented foods; nevertheless their behavior and metabolite production are considerably influenced by the substrate. The purpose of this study was to investigate the growth and production of the most important sensorically and antimicrobially active metabolites of different Lactobacillus strains on Jerusalem artichoke juice. RESULTS: All investigated strains grew well (in the range 10⁹ cfu mL^?1) in the media. The organic acids (lactic acid, 110–337 mmol L^?1; acetic acid, 0–180 mmol L^?1; and succinic acid, 0–79 mmol L^?1), hydrogen peroxide (0.25–1.77 mg L^?1), mannitol (0.06–3.24 g L^?1), acetoin and diacetyl production of strains varies not only according to the species but also from strain to strain, which will be demonstrated and discussed in the paper. CONCLUSION: Our results showed that lactobacilli can be used for the fermentation of Jerusalem artichoke, which in this form could be used, alone or mixed with other raw food material, as a new synbiotic functional food. Copyright © 2011 Society of Chemical Industry     

Inoculated fermentation of orange juice (Citrus sinensis L.) for production of a citric fruit spirit

The yeast Saccharomyces cerevisiae UFLA CA1174 was evaluated for its potential to produce an orange spirit, as a possible alternative to reduce waste and increase income to citrus farmers. The sugar concentration of the orange juice was adjusted to 16ºBrix and the pH to 4.5. The orange juice was inoculated at approximately 7 log CFU/mL, and the fermentation was performed at room temperature until ºBrix stabilization. The yeast used showed high values for the conversion factors of the substrates into ethanol (Y_p/s 0.50 g/g), the volumetric productivity of ethanol (Q_p 1.78 g/L/h), the biomass productivity (P_x 58.47 g/g) and the fermentation efficiency (E_f 97.83%). The sugars were converted quickly, and a high ethanol concentration (58.13 g/L) was achieved after 24 h of fermentation. The orange wine was distilled in a copper alembic, and the head, heart and tail fractions were collected. The orange spirit produced (heart fraction) had high concentrations of acetaldehyde, ethyl acetate, isoamyl alcohol and 2‐phenylethanol. The results showed that orange juice could be a good substrate for fermentation and distillation, and the sensory analysis performed revealed that the produced beverage had good acceptance by the tasters. Copyright © 2013 The Institute of Brewing & Distilling     

Spray drying conditions for orange juice incorporated with lactic acid bacteria

This work aimed to develop an orange juice powder by spray drying with lactic acid bacteria (Lactobacillus plantarum 299v and Pediococcus acidilactici HA‐6111‐2), testing their survival both during drying and storage (room temperature and 4 °C). Initially, the best conditions for spray drying were chosen to allow the best survival of each LAB: (i) inlet air temperature of 120 °C and (ii) 0.5:2 ratio of the orange juice soluble solids and drying agent added (prebiotics: 10 DE maltodextrin or gum Arabic). Survival of LAB was not affected by drying process, and it was higher when cultures were stored at 4 °C. A slightly higher protection was conferred by 10 DE maltodextrin, in the case of L. plantarum and at 4 °C. Pediococcus acidilactici was more resistant during storage at 4 °C, with logarithmic reductions lower than 1 log‐unit. It was demonstrated that it is possible to produce a functional nondairy product, orange juice powder supplemented with prebiotic compounds, containing viable LAB for at least 7 months, when stored at 4 °C.     

Short chain xylooligosaccharides: a potential prebiotic used to improve batter fermentation and its effect on the quality attributes of idli,a cereal–legume‐based Indian traditional food

Xylooligosaccharides (XOS), a potential prebiotic exhibits important technological characteristics and interesting nutritional properties. The major fraction in XOS produced enzymatically from corncob was characterised as β‐d ‐xylopyranosyl‐(1,4)‐d ‐xylanopyranose (xylobiose) using ¹³C and 2D‐HSQC NMR. The use of this XOS as a prebiotic in idli, a cereal/legume‐based fermented cake, and its effect on texture, fermentation and sensory characteristics was investigated. Idli batter was fermented with different concentrations of XOS (0, 0.2, 0.4 and 0.6% w/v) for 4–18 h conventionally. The addition of XOS markedly increased lactic acid bacteria number (9.88 ± 0.08 log cfu g^?1) which resulted in rapid reduction in pH (4.61 ± 0.03) and specific gravity after 6 h of fermentation when compared to conventional batter fermentation for 18 h without XOS (9.46 ± 0.06 log cfu g^?1). Instrumental (colour and texture) and sensory evaluation indicated that the optimum conditions were 0.4% XOS and 6 h fermentation. Idlis with XOS had higher moisture content and a softer texture. Addition of XOS benefits both fermentation and idli quality.     

Bioconversion of agro‐industrial by‐products to lactic acid using Lactobacillus sakei and two Pediococcus spp. strains

The aim of this study was to evaluate the bioconversion efficiency of rich in cellulose agro‐industrial by‐products such as wheat bran (WB), spent distiller's grain with solids (DGS), brewer's spent grain (BSG) and lupin (Lupinus angustifolius L.) wholemeal fraction (LF) to lactic acid (LA) using acid tolerant lactic acid bacteria (LAB) strains Lactobacillus sakei KTU05‐06, Pediococcus acidilactici KTU05‐7 and P. pentosaceus KTU05‐9. Carbohydrase preparation Depol^? 692L was used for the hydrolysis of non‐starch polysaccharides. Analysed raw materials were suitable substrates for LAB propagation and L‐lactic acid production. The lowest pH (3.6) was found in LF medium after 48 h fermentation with P. acidilactici and P. pentosaceus strains. The lowest pH (3.86) was measured in WB fermented with L. sakei, and in DGS and BSG (pH 3.8 and 3.9 respectively) fermented with P. acidilactici. The highest endoxylanase activity was excreted by the P. acidilactici and P. pentosaceus (84 and 69 XU g^?1 respectively), and the highest α‐amylase activity was of L. sakei (255.6 AU g^?1) after 24 h incubation in WB medium. The L‐lactic acid concentration of 86.11 g kg^?1 was reached after the bioconversion of hydrolysed WB in combination with 48 h fermentation by P. pentosaceus KTU05‐9 strain. LA contents between 222 and 282 mg kg^?1 was produced from lupin processing residues via fermentation using P. acidilactici and P. pentosaceus KTU05‐9 strains. The major challenge within the presented study is the viability of tested LAB in cereal waste media and effective LA production at a low pH (3.6–3.8).     

Physical,chemical and microbiological changes during green plant juice fermentation

Protein was precipitated from alfalfa juice by fermentation at 30°C, 35°C and 40°C.During fermentation there was a decrease in the pH, the total non-structural carbohydrate and the solid content while there was an increase in the lactic acid concentration and the population of the lactic acid bacteria in the juice. The lactic acid bacteria, which were initially only about 0·1% to 1·0% of the total bacteria count in the juice, predominated after a period of fermentation, producing mostly lactic acid and considerable amounts of acetic acid but only trace amounts of other volatile fatty acids.The addition of some lactic acid bacteria cultures—Lactobacillus plantarum and Pediococcus cereviseae—to the juice at the beginning of fermentation substantially reduced the lag phase and the final pH of the juice.     

Simultaneous lactic acid and xylitol production from vine trimming wastes

Hemicellulosic hydrolyzates from vineshoot trimmings obtained by dilute sulfuric acid hydrolysis were evaluated for xylitol production by Debaryomyces hansenii NRRL Y‐7426. Bioconversion was not efficient, however, since a mixture of products (mainly ethanol) was achieved. Taking into account that hexoses (such as glucose or mannose) can inhibit xylose metabolism by repression and inactivation of the xylose transport system or catabolic enzymes and that these hemicellulosic hydrolyzates are characterized by a high glucose concentration, a novel technology was developed, sequentially transforming glucose into lactic acid by Lactobacillus rhamnosus followed by fermentation of xylose into xylitol by Debaryomyces hansenii after L. rhamnosus removal by microfiltration. Optimal conditions were achieved using detoxified concentrated hemicellulosic hydrolyzates, after CaCO₃ addition in both stages of fermentation and using nitrogen purges after sampling in order to reduce the oxygen dissolved. Under these conditions 31.5 g lactic acid L^?1 (Q_LA = 1.312 g L^?1 h^?1 and Y_LA/S = 0.93 g g^?1) and 27.5 g xylitol L^?1 (Q_Xylitol = 0.458 g L^?1 h^?1 and Y_Xylitol/S = 0.53 g g^?1) were produced. Finally, lactic acid was selectively recovered using the resin Amberlite IRA 400 (0.0374 g of lactic acid g^?1 of dry resin), allowing a further recovery of xylitol by sequential stages of adsorption, concentration, ethanol precipitation, concentration and crystallization to obtain food‐grade xylitol according to a developed process. Copyright © 2007 Society of Chemical Industry     

Fermentation of beet juice by beneficial lactic acid bacteria

Red beets were evaluated as a potential substrate for the production of probiotic beet juice by four species of lactic acid bacteria (Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus delbrueckii, Lactobacillus plantarum). All the lactic cultures were found capable of rapidly utilizing beet juice for cell synthesis and lactic acid production. However, L. acidophilus and L. plantarum produced a greater amount of lactic acid than other cultures and reduced the pH of fermented beet juice from an initial value of 6.3 to below 4.5 after 48 h of fermentation at 30°C. Although the lactic cultures in fermented beet juice gradually lost their viability during cold storage, the viable cell counts of these lactic acid bacteria except for L. acidophilus in the fermented beet juice still remained at 10⁶–10⁸ CFU/ml after 4 weeks of cold storage at 4°C.     

The occurrence and prevention of ethanol fermentation in high‐dry‐matter grass silage

Ethanol is a common, usually minor fermentation product in ensiled forages, the major product being lactic acid. Occasionally, high levels of ethanol are found in silages. The aim of this study was to determine the incidence of high‐dry‐matter (DM) grass silages containing ethanol as the main fermentation product (ethanol silages), to describe the fermentation process in such silages and to determine the effect of grass maceration prior to wilting and addition of a bacterial inoculant containing Lactobacillus plantarum and Enterococcus faecium strains on fermentation. Twenty‐one laboratory silages produced between 1993 and 1995, 21 farm silages produced between 1980 and 1989 and 36 farm silages produced in 1995 (all produced without additive) were examined for pH and chemical composition. Dry matter (DM) loss during ensilage was determined for the laboratory silages only. Four laboratory silages were identified as ethanol silages. Mean concentrations of ethanol, lactic acid and acetic acid were 48.1, 15.5 and 6.0 g kg⁻¹ DM respectively. In the silages that contained lactic acid as the main fermentation product (lactic acid silages) these values were 7.7, 45.5 and 15.1 g kg⁻¹ DM. Mean DM loss and pH were 62.8 g kg⁻¹ DM and 5.32 respectively for ethanol silages and 24.4 g kg⁻¹ DM and 4.69 for lactic acid silages. There was no difference between ethanol silages and lactic acid silages in the mean concentration of ammonia‐N (94 g kg⁻¹ total N), and butyric acid was not detected (<0.2 g kg⁻¹ DM), indicating that both types of silages were well preserved. Analysis of the composition of the grass at ensiling showed a positive correlation between the concentration of soluble carbohydrates and the development into ethanol silage. Analysis of the farm silages indicated that 29% of the silages produced between 1980 and 1989 and 14% of those produced in 1995 were ethanol silages. Maceration prior to wilting and addition of silage inoculant improved lactic acid fermentation and prevented high ethanol levels. The micro‐organisms responsible for ethanol fermentation as well as the implications of feeding ethanol silages to livestock remain to be resolved. © 2000 Society of Chemical Industry     

Continuous beer fermentation – diacetyl as a villain

This work tested the viability of producing beer of good quality after maturation of green beer obtained by primary continuous fermentation of high‐gravity wort using an airlift bioreactor with flocculated biomass. Fermentation performance of the tested setup was unique as it reached a maximum saccharide consumption rate of 9.43 g L^?1 h^?1 and an ethanol productivity of 3.75 g L^?1 h^?1. Despite the high levels of diacetyl present in the green beer, a regular maturation was able to reduce it to below threshold values in up to 15 days. It was observed that diacetyl production was strongly correlated with wort composition injected into the system, rather than with the large amount of biomass immobilized in the bioreactor (up to 727 × 10⁶ cell mL^?1). Organoleptic tests showed that the maturated beer had no major defects. Copyright © 2015 The Institute of Brewing & Distilling     

Improvement of L(+)‐lactic acid production from cassava wastewater by Lactobacillus rhamnosus B 103

BACKGROUND: L (+)‐Lactic acid is used in the pharmaceutical, textile and food industries as well as in the synthesis of biodegradable plastics. The aim of this study was to investigate the effects of different medium components added in cassava wastewater for the production of L (+)‐lactic acid by Lactobacillus rhamnosus B 103. RESULTS: The use of cassava wastewater (50 g L^?1 of reducing sugar) with Tween 80 and corn steep liquor, at concentrations (v/v) of 1.27 mL L^?1 and 65.4 mL L^?1 respectively led to a lactic acid concentration of 41.65 g L^?1 after 48 h of fermentation. The maximum lactic acid concentration produced in the reactor after 36 h of fermentation was 39.00 g L^?1 using the same medium, but the pH was controlled by addition of 10 mol L^?1 NaOH. CONCLUSION: The use of cassava wastewater for cultivation of L. rhamnosus is feasible, with a considerable production of lactic acid. Furthermore, it is an innovative proposal, as no references were found in the scientific literature on the use of this substrate for lactic acid production. Copyright © 2010 Society of Chemical Industry     

Effect of pH,aeration and feeding non‐sterilized agave juice in a continuous agave juice fermentation

BACKGROUND: Continuous cultures have been used since the 1950s in beer and wine fermentations due to their higher productivities compared to traditional batch systems; nevertheless, the tequila industry has not taken advantage of the possible improvements that continuous fermentations could offer. In this work, the effect of pH, aeration and feeding of non‐sterilized medium, on the fermentative capability of two Saccharomyces cerevisiae strains (S1 and S2) cultured in continuous fermentation, using agave juice as the fermentation medium, were studied. RESULTS: In continuous cultures, the control of the medium pH (set point at 4) did not have a significant effect on fermentation efficiency compared to fermentations in which the pH was not controlled (pH 2.5 ± 0.3). Conversely, aeration of the cultures of both strains improved biomass production and consumption of reducing sugars and ammonium. The aeration also significantly augmented ethanol production only for S1 cultures (P < 0.05). Furthermore, the feeding of medium, either sterilized or not, did not show significant differences on the production of ethanol for S1 cultures. Higher concentrations of acetoin, succinic acid and diacetyl were found in the cultures fed with non‐sterilized medium. CONCLUSIONS: Compared to S2, S1 has a better fermentative performance in continuous non‐sterilized medium fermentations. Not controlling the pH during the cultures could prevent the possibility of microbial contamination as a result of the extreme medium acidity (pH 2.5 ± 0.3). This work showed the possibility of scaling up agave juice continuous fermentation feeding non‐sterilized medium with no control of pH. Copyright © 2010 Society of Chemical Industry     

Evaluation of the conditions of carotenoids production in a synthetic medium by Sporidiobolus salmonicolor (CBS 2636) in a bioreactor

This work studied the cultivation conditions for the production of carotenoids by Sporidiobolus salmonicolor (CBS 2636) in a bioreactor. A Plackett–Burman design was used for the screening of the most important factors, followed by a complete second order design, to maximise the concentration of total carotenoids. The maximum concentration of 3425.9 μg L^?1 of total carotenoids was obtained in a medium containing 80 g L^?1 glucose, 15 g L^?1 peptone and 5 g L^?1 malt extract, with an aeration rate 1.5 vvm, 180 r.p.m., 25 °C and an initial pH of 4.0. Fermentation kinetics showed that the maximum concentration of total carotenoids was reached after 90 h of fermentation. Carotenoid bio‐production was partially associated with cell growth. The specific carotenoid production (Y_P/X) was 238 μg carotenoids/g cells, whereas Y_P/S (substrate to product yield) was 41.3 μg g^?1. The specific growth rate (μ_x) was 0.045 h^?1. The highest cell and total carotenoid productivity were 0.19 g L^?1 h^?1 and 56.9 μg L^?1 h^?1, respectively.