Innovative approaches for amino acid production via consolidated bioprocessing of agricultural biomass

Agricultural plantations in Indonesia and Malaysia yield substantial waste, necessitating proper disposal to address environmental concerns. Yet, these wastes, rich in starch and lignocellulosic content, offer an opportunity for value-added product development, particularly amino acid production. Traditional methods often rely on costly commercial enzymes to convert biomass into fermentable sugars for amino acid production. An alternative, consolidated bioprocessing, enables the direct conversion of agricultural biomass into amino acids using selected microorganisms. This review provides a comprehensive assessment of the potential of agricultural biomass in Indonesia and Malaysia for amino acid production through consolidated bioprocessing. It explores suitable microorganisms and presents a case study on using Bacillus subtilis ATCC 6051 to produce 9.56 mg/mL of amino acids directly from pineapple plant stems. These findings contribute to the advancement of sustainable amino acid production methods using agricultural biomass especially in Indonesia and Malaysia through consolidated bioprocessing, reducing waste and enhancing environmental sustainability.

Valorization of pineapple rind for bromelain extraction using microwave assisted technique: optimization, purification, and structural characterization

Huge amount of waste is generated by the pineapple processing industries which raises concerns regarding its safe disposal into the environment. This ever-increasing problem of waste management can be solved by the valorization of pineapple by-products to high-value compounds. The extraction of proteolytic enzyme, bromelain from pineapple rind using green techniques can help to overcome the drawbacks associated with conventional methods. In the present study, the extraction of bromelain from pineapple rind using microwave assisted technique resulted in considerable amount of proteolytic activity (127.8 U/mL) and protein content (2.55 mg/mL). The optimized extraction conditions were found as 200 W microwave power, 1:5 solid/ liquid ratio and after treatment time of 10 min. Highest specific activity (512 U/mg) of bromelain was obtained after using gel filtration chromatography. FTIR result confirmed the presence of functional groups in bromelain, whereas, XRD analysis indicated the semi-crystalline nature of bromelain. The results indicated MAE as an effective green technique for the extraction of bromelain from pineapple rind. The proteolytic action of the extracted bromelain makes it a suitable functional ingredient for its applications in bakery, dairy, and seafood processing industries.

Effect of Post-Washing on Textural Characteristics of Carbon Materials Derived from Pineapple Peel Biomass

Porous carbon materials have been widely used to remove pollutants from the liquid-phase streams. However, their limited pore properties could be a major problem. In this work, the effects of post-washing methods (i.e., water washing and acid washing) on the textural characteristics of the resulting biochar and activated carbon products from pineapple peel biomass were investigated in the carbonization and CO2 activation processes. The experiments were set at an elevated temperature (i.e., 800 °C) holding for 30 min. It was found that the enhancement in pore property reached about a 50% increase rate, increasing from 569.56 m2/g for the crude activated carbon to the maximal BET surface area of 843.09 m2/g for the resulting activated carbon by water washing. The resulting activated carbon materials featured the microporous structures but also were characteristic of the mesoporous solids. By contrast, the enhancement in the increase rate by about 150% was found in the resulting biochar products. However, there seemed to be no significant variations in pore property with post-washing methods. Using the energy dispersive X-ray spectroscopy (EDS) and the Fourier Transform infrared spectroscopy (FTIR) analyses, it showed some oxygen-containing functional groups or complexes, potentially posing the hydrophilic characters on the surface of the resulting carbon materials.

The Chemical Characteristics and In Vitro Degradability of Pineapple By-Products as Potential Feed for Ruminants

Pineapple fruit, which is cultivated in tropical and subtropical areas, is processed by the food industry, generating a large amount of waste. Using pineapple by-products in animal nutrition could reduce feeding costs and contribute to the containment of pollution. The chemical composition and the in vitro fermentation of five pineapple by-products (crown, bud end, peel, core, and pomace) from two West African pineapple varieties (Smooth Cayenne-SC and Sugarloaf-SL) were evaluated. Significant differences were observed between the varieties and by-products. The dry matter (DM) content was low and superimposable between varieties, averaging 17.7%. On a DM basis, pomace showed the highest protein content (SC 8.10% and SL 8.81%, p < 0.001), whereas the crown showed the highest (p < 0.001) NDF content (47.62% and 39.01% for SC and SL, respectively). Due the high sugar content, the core and pomace showed high in vitro organic matter degradability (SC: 85.09% and SL: 83.98%), estimated metabolizable energy (SC: 7.91 KJ/kg and SL: 7.66 KJ/kg), and volatile fatty acid production (96.86 mmol/g and 90.62 mmol/g). Based on chemical composition and in vitro digestibility results, this study suggests that pineapple by-products have the potential to be used in ruminants' diets, considering the crown, bud end, and peel as fiber sources and the core and pomace as substitutes or supplements to concentrate feedstuffs. Further research should be conducted on the storability of these by-products through in vivo trials evaluating animals' performances and the quality of their products.

Pineapple peel waste valorization for extraction of bio-active compounds and protein: Microwave assisted method and Box Behnken design optimization

Pineapple peel waste (PPW) is obtained in huge quantities out of pineapple canning industries and it is found to be rich in bioactive compounds with antioxidant activity and an opulent source of bromelain protein having commercial importance. To fulfil the purpose, microwave assisted extraction was considered. Three parameters varied were solvent to substrate ratio, microwave power and extraction time. The independent variables were solvent to substrate ratio (10:1 mL/g to 20:1 mL/g), microwave power (300 W-600 W) and extraction time (40 min-50 min). Optimization was done with three factors and three level Box- Behnken Design (BBD). Each of the experiment has been analysed for Total phenolic content (TPC), Total flavonoid content (TFC), Total tannin content (TTC) as well as for protein content. The Folin- Ciocalteu method was utilized for analysing TPC, TTC and the colorimetric method (AlCl₃) was used for the analysis of TFC, protein content was analysed by lowry's method and antioxidant activity making use of 2,2-diphenyl-1-picrylhydrazyl (DPPH). The p values were less than 0.05 which showed all the four models were significant. The experimental values and the predicted values were harmonious for the optimum conditions. The optimum condition obtained out of BBD were solvent to substrate ratio of 20:1 mL/g, microwave power of 600 W and extraction time 40 min. Antioxidant activity for the extract was found out by DPPH assay under the optimized conditions was 75% along with proteolytic activity of bromelain as 1647.612 GDUg_concentrate^-1.

Pineapple waste in animal feed: A review of nutritional potential, impact and prospects

Pineapple is a commodity and economic fruit with a high market potential worldwide. Almost 60 % of the fresh pineapple, such as peels, pulp, crowns and leaves, are agricultural waste. It is noteworthy that the waste has a high concentration of crude fibre, proteins, ascorbic acid, sugars and moisture content. The pineapple waste utilisation in animal feed has recently drawn the attention of many investigators to enhance growth performance and concomitantly reduce environmental pollution. Its inclusion in animal feed varies according to the livestock, such as feed block, pelleted or directly used as a roughage source for ruminants. The pineapple waste is also fermented to enrich the nutrient content of poultry feed. To date, the inclusion of pineapple waste in animal feed is optimistic only not for livestock but also for farmed fish. Indeed, it is an ideal strategy to improve the feed supply to the farm. This paper aims to overview the source, nutritional composition, and application of pineapple waste in animal feed. The recent findings on its effect on animal growth performance, nutrition and disease control are discussed comprehensively and summarised. The review also covers its benefits, potential impacts on sustainable farming and future perspectives.

Pineapple processing waste (PPW): bioactive compounds, their extraction, and utilisation: a review

Fruits and vegetable processing industries contribute to the largest portion of food waste. With changing diet habits, the demand for the production and processing of fruits and vegetables has increased greatly to fulfil the rising demand amongst the masses. Waste generation begins from the harvesting of raw material until it gets processed. Pineapple processing industries produce processing waste (peel, core, pomace, and crown) which are rich in various bioactive compounds. In most cases, the by-products contain larger amounts of valuable compounds which have higher nutritional and therapeutic importance than its final produce. Researchers have studied the potential of pineapple wastes primarily for the extraction of enzymes (bromelain, pectinase, xylanase and cellulase) and secondarily as a low-cost substrate to produce dietary fibre, organic acids, and phenolic antioxidants. This review describes the bioactive compounds in pineapple wastes, their extraction techniques, and their potential applications as a polymer material, bio-sorbents, bioethanol and vanillin production, etc. It focuses primarily on bioactive compounds that have functional and medicinal value and can be used independently or incorporated with other ingredients to form the valorised product.

Graphic abstract

Bioprocessing of pineapple waste biomass for sustainable production of bioactive compounds with high antioxidant activity

The effect of temperature, moisture content and pH during solid-state fermentation (SSF) of MD2 pineapple peel with Rhizopus oryzae (MUCL 28168) was evaluated on the release of bioactive compounds with antioxidant capacity. Applying a central composite design, it was found that temperature had a significant effect (p < 0.05) on the total phenolic content and DPPH antioxidant activity while for the ABTS radical elimination activity, the factor that presented a significant effect was the pH (p < 0.05); as this factor increases, the antioxidant activity enhances. The optimal conditions for fermentation process were 80% of moisture content, pH 5.5, temperature 37.3 °C and 24 h of process to maximize phenolic content and antioxidant activity. Gallic acid, chlorogenic acid, caffeic acid and cinnamic acid were identified in the extracts by HPLC analysis. These results permit to conclude that SSF of pineapple peel is an effective bioprocess for the release of phenolic compounds with antioxidant activity.

Graphical abstract

The effects of fermented pineapple residue on growth performance, meat quality, and rumen microbiota of fattening Simmental bull

In this study, silage Pennisetum sinese Roxb-based diet was replaced with fermented pineapple residue (FPR) at the replacement ratio of 0% (CON), 25% (T25), and 50% (T50) in fattening Simmental bulls for 30 days to evaluate the effects of FPR on growth performance, serum indexes, and ruminal characteristics. A total of 30 Simmental bulls (546 ± 44 kg initial BW) were allocated to three groups according to a completely randomized design. On day 30, the slaughter performance and meat quality were determined. Rumen fluids were collected for analyzing the rumen fermentation parameters and microbiota composition on day 30. The results showed that the average daily weight gain increased (P < 0.05) as the proportion of FPR rose. Within treatments, the T25 group reached more profit (5.34 RMB per day per bull) than CON while T50 was 3.69. The content of crude fat, cysteine, and proline in the muscle of T50 increased significantly (P < 0.05). The amounts of tyrosine, proline, and phenylalanine were significantly increased in the T25 (P < 0.05). The beta diversity analysis showed significant differences among the rumen bacterial flora of each group (P < 0.05). In the T25 group, the relative abundance of Spirochaetes decreased significantly (P < 0.05). The relative abundance of Lachnospiraceae_bacterium_RM44 was significantly lower (P < 0.05). Thus, FPR could improve the growth performance, economic benefits, and meat quality without adverse effects on ruminal characteristics.

Bromelain: A Potent Phytomedicine

The commercially available protein-digesting enzyme bromelain is derived from the pineapple fruit or stem. Bromelain from fruit and stems are produced in different ways and has varied enzyme compositions. “Bromelain” often refers to the "stem bromelain". Bromelain is a combination of several thiol endopeptidases and others including various protease inhibitors, glucosidase, cellulase, phosphatase, peroxidase, and escharase. Studies conducted in both the lab and on animals show that bromelain has a variety of fibrinolytic, anti-edematous, antithrombotic, and anti-inflammatory effects. The body can absorb bromelain to a significant extent without it ceasing its proteolytic activity or having any negative side effects. Numerous therapeutic advantages of bromelain include wound debridement, improved drug absorption, and the management of sinusitis, bronchitis, angina pectoris, surgical trauma, and thrombophlebitis. Additionally, it treats numerous cardiovascular conditions, diarrhoea, and osteoarthritis. Bromelain also encourages apoptotic cell death and exhibits some anti-cancerous properties. This review compiles the crucial traits, medical and dental uses of bromelain as well as its potential mechanism of action.

Preparation and Characterization of Porous Materials from Pineapple Peel at Elevated Pyrolysis Temperatures

In this work, pineapple peel (PP) was reused as a precursor in biochar (BC) production at elevated temperatures (i.e., 500−900 °C) for residence times of 0−60 min. The findings showed that pyrolysis temperature and residence time played a vital role in pore development. As pyrolysis temperature increased from 800 to 900 °C for residence times of 20 and 60 min, the data on the Brunauer−Emmett−Teller (BET) surface area of the resulting biochar products significantly jumped from 11.98−32.34 to 119.43−133.40 m2/g. In addition, there was a significant increase in the BET surface area from 1.02 to 133.40 m2/g with the residence time of 0 to 20 min at 900 °C. From the data of the nitrogen adsorption−desorption isotherms and the pore size distribution, both micropores (pore diameters of <2.0 nm) and mesopores (pore diameters of 2.0−50.0 nm) are present in the PP-based biochar products. Due to its good fittings in the pseudo-second-order model and its hydrophilic nature, as seen in the Fourier transform infrared spectroscopy (FTIR), the resulting biochar could be a porous material to be used for the effective removal of cationic compounds (i.e., methylene blue (MB)) from liquid phases.

Bromelain, a Group of Pineapple Proteolytic Complex Enzymes (Ananas comosus) and Their Possible Therapeutic and Clinical Effects. A Summary

Bromelain is a complex combination of multiple endopeptidases of thiol and other compounds derived from the pineapple fruit, stem and/or root. Fruit bromelain and stem bromelain are produced completely distinctly and comprise unique compounds of enzymes, and the descriptor “Bromelain” originally referred in actuality to stem bromelain. Due to the efficacy of oral administration in the body, as a safe phytotherapeutic medication, bromelain was commonly suited for patients due to lack of compromise in its peptidase efficacy and the absence of undesired side effects. Various in vivo and in vitro studies have shown that they are anti-edematous, anti-inflammatory, anti-cancerous, anti-thrombotic, fibrinolytic, and facilitate the death of apoptotic cells. The pharmacological properties of bromelain are, in part, related to its arachidonate cascade modulation, inhibition of platelet aggregation, such as interference with malignant cell growth; anti-inflammatory action; fibrinolytic activity; skin debridement properties, and reduction of the severe effects of SARS-Cov-2. In this paper, we concentrated primarily on the potential of bromelain’s important characteristics and meditative and therapeutic effects, along with the possible mechanism of action.

Feed intake, digestibility, and energy contents in growing bull fed pineapple crop waste silage in different planes of nutrition

The objective of this study was to nutritionally evaluate the use of pineapple crop waste silage in the feeding of growing bull in different planes of nutrition. We used eight non-castrated growing bull housed in individual covered pens, provided with free access to water and individual trough. Two balanced Latin squares conducted simultaneously were used. Treatments consisted of four planes of nutrition (L), formed by multiples of maintenance, i.e., L = ME/Mm; they were ME/Mm, ME/1.5Mm, ME/2Mm, and ME/2.7Mm. The intake of nutrients in diets was determined by the difference between the total mass of food offered and the mass of orts. To determine nutrient digestibility and nitrogen balance, total feces, and urine, collections were performed for seven consecutive days in each animal per period. The increase in planes of nutrition affected (P < 0.05) nutrient intake between L = 1 and L = 1.5. However, there was no effect nutrients intake to 1.5, 2, and 2.7. Nutrient digestibility was affected by the increase in planes of nutrition (P < 0.05), except for dCF (P = 0.0659). Digestible and metabolizable energies were affected (P < 0.05) by the increase in nutritional plans, as well as nitrogen balance. In conclusion, the pineapple crop waste silage presents itself as a good forage alternative for cattle diets, especially during forage shortage periods. Inclusion in the diet at 2.7 × the maintenance level does not compromise growing bull performance. However, the increases in planes of nutrition reduce the digestible energy contents of the diet.

Nutrient recovery from pineapple waste through controlled batch and continuous vermicomposting systems

The largest portion of pineapple peels and pulp generated from production points is disposed of haphazardly contributing to a number of environmental and health challenges. However, these wastes contain valuable plant nutrients that could be recovered to boost soil fertility, and increase agricultural production. This study evaluated the variation in physico-chemical parameters in batch and continuous vermicomposting systems as potential pathways for nutrient recovery from pineapple waste. The study compared the efficiency of waste reduction and nutrient recovery for batch (B), and continuous (C) vermicomposting systems during a 60-day period. The substrates were pineapple peels (PW), and cattle manure (CM) fed in a ratio of 4:1 (w/w). Control reactors were fed with 100% CM in both the feeding modes. Results indicated that waste degradation was 60%, and 54% while earthworm biomass increased by 57% and 129% for BPW, and CPW, respectively. pH significantly decreased with time in both systems. Total phosphorous increased with vermicomposting time with that of B being significantly higher than C systems. Nitrogen, potassium, and sodium significantly increased in the control experiments while the three elements significantly reduced for BPW, and CPW owing to high leachate production in the latter. The N, P, K, and C retention in vermicompost was 24.2%, 90.4%, 67.5%, 41.1%, and 32.6%, 91.2%, 79.3%, 46.1%, for BPW and CPW, respectively. Continuous systems produced higher earthworm biomass and retained more nutrients in vermicompost than batch systems, and can therefore, be recommended as better systems for pineapple waste vermicomposting.

Minimizing Organic Waste Generated by Pineapple Crown: A Simple Process to Obtain Cellulose for the Preparation of Recyclable Containers

In this study, cellulose was obtained from the residues of pineapple crown by means of simple acid pretreatment and subsequent alkaline treatment. The pretreatment consisted of washing, drying, and chopping with high shear at pH = 5 under heating. The content of cellulose, hemicellulose, and lignin in the pineapple crown was determined by chemical methods. The cellulose obtained was compared with commercial cellulose by Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis, and X-ray diffraction (XDR). Thus, from the obtained fiber cellulose, a food container was prepared, and its physical-mechanical properties were determined. Then, after alkali treatment, the purity of cellulose was 84.7% from the pineapple crown (56.0%) and was compared with commercial cellulose (95%). FTIR results confirmed the removal of the non-cellulosic compounds after alkali treatment. The maximum pyrolysis temperature increased to 356 °C, higher than the original fiber (322 °C), indicating greater thermal stability after chemical treatment. Furthermore, the crystallinity increased to 68% with respect to the original fiber (27%). The physical properties of the container showed a decrease in the parameters in wet 95% RH, as expected, thus facilitating its reuse. These results indicate that the pineapple crown cellulose can be obtained with significant purity, from a single chemical treatment. In addition, this polymorphous cellulose can be used to make ecofriendly reusable food containers.

Maintaining Physicochemical, Microbiological, and Sensory Quality of Pineapple Juice (Ananas comosus, Var. ‘Queen Victoria’) through Mild Heat Treatment

Shelf life of freshly prepared pineapple juice is short and requires refrigerated conditions of storage. Mild heat treatment remains the easiest way to prolong juice shelf life for small companies. This study was constructed to assess pineapple cv. Queen Victoria juice shelf life from a broad examination of its quality and to propose the most appropriate thermal treatment to increase shelf life without any perceptible decrease in quality. From 25 independent batches of pineapple, collected in different areas and seasons from Reunion Island, the variability of juice physicochemical and microbiological quality was determined. Juice pH values were the highest for fruit harvested in summer, but the juice acidity remained low enough to prevent pathogen spore-forming bacteria growth. During storage at 4 °C, color was modified, and yeasts and molds were the main microbial group exhibiting growth. Assessment of sensory quality resulted in the proposal of a shelf life comprising between three and seven days. Compared to higher temperatures, heat treatment at 60 °C was enough to ensure a good microbiological quality for 30 days, but sensory characteristics and color changes led to the proposal of a shelf life of seven days for pineapple juice treated at 60 °C.

Effects of concentrate levels and pineapple stem on growth performance, carcass and meat quality of dairy steers

The objective of this study was to determine a suitable level of concentrate using pineapple stem by-product as a roughage source for the growth performance, carcass traits and meat quality of Holstein steer. Forty Holstein steers with an average initial body weight of 404.2 ± 38.2 kg (18 months of age) were used in a completely randomised design. The treatments consisted of four levels of restricted concentrate (4, 5, 6 and 7 kg/head/day as fed basis), and the animals were fed ad libitum pineapple stem by-product as a roughage source. The data were analysed by using orthogonal polynomial contrasts of trend response, represented by the linear and quadratic effects of the concentrate levels. Total dry matter intake (DMI) increased with increasing concentrate levels and was the highest in the dairy steer fed 6 kg/head/day (P < 0.05). Pineapple stem by-product intake was decreased by 5.51, 4.70, 4.04 and 2.59 kg DM/day with increasing concentrate levels, and the linear effect was significant (P < 0.01). Ruminal pH decreased with increasing concentrate levels (6.54, 6.46, 6.12 and 6.00), and the linear effect was significant (P < 0.01). The overall carcass characteristics were not affected by the treatments. The steers fed 4 kg/head/day of the concentrate presented the lowest feed cost per gain. These results indicated that pineapple stem by-product is suitable for use as a roughage source.

Process of fruit peel waste biorefinery: a case study of citrus waste biorefinery, its environmental impacts and recommendations

Fruit peels are a rich source of cellulose, hemicellulose, phenolic compounds, and terpenic compounds. Thus, they have the potential to be a novel renewable, sustainable, and low-cost raw material (source) for the production of several value-added products based on framework and concepts such as waste hierarchy that includes biofertilizers, dietary fiber, animal feed, industrial enzymes, substrate for the bioactive compounds production, synthesis of nanomaterials, and clean energy (from residual biomass). With a view of evaluating the environmental burden of biorefinery, a life cycle assessment (LCA) is performed for a representative citrus waste (CW) biorefinery. The functional unit used for LCA was set as 2500 kg of CW processed. The overall GWP was observed to be 937.3 kg CO₂ equivalent per 2500 kg of CW processed. On further analysis of the environmental impact, it was found that different steps contributed significantly, as shown by the various environmental indicator values. Alternative advanced process intensification technologies like microwave and ultrasound-assisted steps replacing the conventional steps when implemented show considerable reduction in environmental indicator values. The variations in the contribution to environmental indicators should be considered during the design and process selection of biorefineries.

Valuable Compound Extraction, Anaerobic Digestion, and Composting: A Leading Biorefinery Approach for Agricultural Wastes

In a society where the environmental conscience is gaining attention, it is necessary to evaluate the potential valorization options for agricultural biomass to create a change in the perception of the waste agricultural biomass from waste to resource. In that sense, the biorefinery approach has been proposed as the roadway to increase profit of the agricultural sector and, at the same time, ensure environmental sustainability. The biorefinery approach integrates biomass conversion processes to produce fuels, power, and chemicals from biomass. The present review is focused on the extraction of value-added compounds, anaerobic digestion, and composting of agricultural waste as the biorefinery approach. This biorefinery approach is, nevertheless, seen as a less innovative configuration compared to other biorefinery configurations, such as bioethanol production or white biotechnology. However, any of these processes has been widely proposed as a single operation unit for agricultural waste valorization, and a thoughtful review on possible single or joint application has not been available in the literature up to now. The aim is to review the previous and current literature about the potential valorization of agricultural waste biomass, focusing on valuable compound extraction, anaerobic digestion, and composting of agricultural waste, whether they are not, partially, or fully integrated.

Use of agro-industrial residue from the canned pineapple industry for polyhydroxybutyrate production by Cupriavidus necator strain A-04

BACKGROUND

Pineapple is the third most important tropical fruit produced worldwide, and approximately 24.8 million tons of this fruit are produced annually throughout the world, including in Thailand, which is the fourth largest pineapple producer in the world. Pineapple wastes (peel and core) are generated in a large amount equal to approximately 59.36% based on raw material. In general, the anaerobic digestion of pineapple wastes is associated with a high biochemical oxygen demand and high chemical oxygen demand, and this process generates methane and can cause greenhouse gas emissions if good waste management practices are not enforced. This study aims to fill the research gap by examining the feasibility of pineapple wastes for promoting the high-value-added production of biodegradable polyhydroxybutyrate (PHB) from the available domestic raw materials. The objective of this study was to use agro-industrial residue from the canned pineapple industry for biodegradable PHB production.

RESULTS

The results indicated that pretreatment with an alkaline reagent is not necessary. Pineapple core was sized to - 20/+ 40 mesh particle and then hydrolyzed with 1.5% (v/v) H₂SO₄ produced the highest concentration of fermentable sugars, equal to 0.81 g/g dry pineapple core, whereas pineapple core with a + 20 mesh particle size and hydrolyzed with 1.5% (v/v) H₃PO₄ yielded the highest concentration of PHB substrates (57.2 ± 1.0 g/L). The production of PHB from core hydrolysate totaled 35.6 ± 0.1% (w/w) PHB content and 5.88 ± 0.25 g/L cell dry weight. The use of crude aqueous extract (CAE) of pineapple waste products (peel and core) as a culture medium was investigated. CAE showed very promising results, producing the highest PHB content of 60.00 ± 0.5% (w/w), a cell dry weight of 13.6 ± 0.2 g/L, a yield ( YP/S ) of 0.45 g PHB/g PHB substrate, and a productivity of 0.160 g/(L h).

CONCLUSIONS

This study demonstrated the feasibility of utilizing pineapple waste products from the canned pineapple industry as lignocellulosic feedstocks for PHB production. C. necator strain A-04 was able to grow on various sugars and tolerate levulinic acid and 5-hydroxymethyl furfural, and a detoxification step was not required prior to the conversion of cellulose hydrolysate to PHB. In addition to acid hydrolysis, CAE was identified as a potential carbon source and offers a novel method for the low-cost production of PHB from a realistic lignocellulosic biomass feedstock.