Complete Granulation Research Articles

Aerobic granulation and bioresource production under intermittent saline stress

Aerobic Granular Sludge (AGS) systems have gained prominence for liquid waste treatment and bioresource recovery. In this regard, various strategies are employed to accelerate granulation processes in sequencing batch reactors (SBRs) and maximize stability and bioresource production. Intermittent stress supplementation can facilitate granule development, promoting slow-growth microorganisms. At the same time, osmotic stress may enhance bioresource production. In this study, an AGS reactor control with no saline stress (R1) was compared to two AGS systems operated under constant (R2) and intermittent (R3) saline stress in terms of efficiency, stability and bioresource productions (alginate-like exopolysaccharides-ALE and tryptophan). Granulation occurred around day 59 and 21 in R2 and R3, respectively, while complete granulation was not achieved in R1 within the 80-day operational period. However, SBRs performed well after 45 days, with 70% of the biomass being granular. The production of the biopolymer ALE remained more stable in reactors with osmotic stress compared to R1. The microbiological analysis revealed specific responses and adaptations to environmental factors, with genera such as Thauera and Pseudofulvimonas showing higher abundance in reactors with complete granulation, indicating a positive correlation with saline conditions (5 g/L). These insights are crucial for optimizing the performance of AGS systems in future applications, emphasizing the benefits of intermittent saline stress in promoting rapid granulation, stability in bioresource production, contaminant removal, and robust granule formation.

Turning alkalinity deficiency-induced metabolic disorder into an opportunity for promoting granulation and enhancing heat generation

Shortage of alkalinity is a common problem in treating low carbon/nitrogen (C/N) wastewater and industrial influents. It negatively affects system stability and efficiency, but its positive effects remain unclear. To address this issue, insufficient (R1: 400 mg CaCO3/L) and sufficient alkalinity (R2: 750 mg CaCO3/L) levels were established in our study, where R1 served as the experimental group and R2 as the control group. In the experimental group, alkalinity deficiency deteriorated the nitrification and phosphorus removal process by reducing the abundance of functional microbes (Nitrosomonas, genus ammonia-oxidizing bacteria, AOB, and Dechloromonas, genus polyphosphate-accumulating organisms, PAOs) and genes (hao). At the same time, the alkalinity deficiency enriched slow-growing functional microbes (Candidatus_Competibacter, genus glycogen-accumulating organisms, GAOs) and key genes (nirK, norB, nosZ, acnB, fumA, fumB) increased the content of extracellular polymeric substances (EPS) and the ratio of protein to polysaccharide (PN/PS). By day 113, over 87 % of the particles were larger than 200 μm, and complete granulation was achieved. Microbial energy metabolism further indicated that alkalinity deficiency diverted some energy to non-growth metabolism, thereby enhancing microbial heat generation. Our results highlight an innovative approach, using the setting of insufficient alkalinity conditions to improve heat recovery and address the challenges of WWTPs. These research findings are in favor of wastewater treatment plants seeking to meet multiple sustainable objectives, including improving water quality, saving footprint, and maximizing energy recovery.

The shrapnel-crushed wounds in dogs: status evaluation and therapy for wound healing

Determining the clinical and laboratory status of animals with crushed wounds as a result of the traumatic effect of ammunition fragments, as well as the wound healing effect of ecologically safe drugs based on natural beekeeping products is of great importance under the conditions of the animals' stay in the war zone and territories subject to rocket-bomb and artillery fire. The aim of the research is to study the clinical condition of dogs with shrapnel-crushed wounds, observing its dynamics during systemic therapy and evaluating the therapeutic effect of wound healing using the universal biological ointment Unibiol®. During the research, various physical, hematological, biochemical, hemorheological, hemodynamic, and statistical methods were employed. Six animals with shrapnel-crushed wounds on their limbs and groin were analyzed. It was established that due to the traumatic factor, injuries in dogs are characterized by extensive tissue destruction and deconstruction. The overall condition of the animals, based on clinical signs, is described as toxemic-septic. Hematological changes such as anemia, leukocytosis, thrombocytopenia, left shift in the nucleus, monocytosis, and lymphocytosis indicate a systemic inflammatory reaction and a septic state in the dogs' bodies. Biochemical studies revealed hypoalbuminemia leading to hypoproteinemia, creatinine elevation, uremia, elevated levels of indicator transaminases, suggesting multi-organ failure. A significant decrease in circulating blood volume, increased spontaneous platelet aggregation, characterizes a moderate traumatic circulatory shock, while a 5-fold increase in the circulation of D-dimer levels indicates a significant potential for disseminated intravascular coagulation syndrome. Following infusion and antibiotic therapy, wound sanitation over 5 days led to a significant restoration of the clinical-laboratory status of the injured dogs, setting the stage for Unibiol® ointment wound-healing therapy. As a result of the treatment conducted over 21 days, the wound defect healed with the formation of complete granulation tissue and an elastic scar. The clinical trials conducted allow recommending Unibiol® ointment for effective and environmentally safe healing of severe shrapnel-crushed wounds.

Effects of high-concentration influent suspended solids on aerobic granulation in sequencing batch reactors treating real textile wastewater

The formation of aerobic granular sludge (AGS) in real textile wastewater (TWW) is time-consuming and challenging. The present study investigated the effects of high-concentration influent suspended solids (SS) on aerobic granulation, pollutant removal, microbial activity, and community in the real TWW treatment by using two sequencing batch reactors (R1: 41.7 ± 22.8 mg influent-SS/L; R2: 416.1 ± 21.4 mg influent-SS/L). The results showed that complete granulation was achieved in R1 within 97 days (SVI30: 34.5 mL/g, SVI30/SVI5 = 0.91), while it only required 52 days in R2 (SVI30: 18.2 mL/g, SVI30/SVI5 = 0.92). The high-concentration influent SS also enhanced compactness and settleability of AGS. Long-term adaption of sludge improved the COD removal from real TWW, which was possibly due to the increase in phyla Firmicutes and Actinobacteria abundances. The real TWW did not adversely affect the nitrification process as indicated by the high NH4+-N removal in both reactors (>93 %). Although the formation of compact AGS in R2 did not exhibit better removal performance under the present experimental condition, it exhibited the potential for better COD removal from real TWW as indicated by the higher microbial activity and functional bacterial abundances in R2 than in R1.

Compact pilot-scale aerobic granular sludge system treating real wastewater continuously for over 500 days

This long-term investigation provides a step-wise optimization of a pilot-scale continuous flow reactor (CFR, total volume ∼ 200 L) using aerobic granular sludge (AGS) to treat municipal wastewater (MW) at temperatures of 18.2 ± 1.8 °C and with organic loading rates of 1.39 ± 0.89 kg COD·m−3·d−1. Short settling times of about 10 min which led to a high selection pressure allowed for a complete granulation after day 47 — i.e., >80 % of the mixed liquor suspended solids (MLSS) larger than 200 μm in diameter and sludge volume indexes of ∼40 mL·g−1. Following a start-up and optimization period of 187 days, the system was stably operated with ∼6.1 g MLSS·L−1 over one year. The best-performance was achieved with an aerobic/anaerobic volume ratio of 2/1 and intermittent aeration. Furthermore, for most of the time a NH4+-N removal of 99 % was possible with low oxygen concentrations (2.0 to 2.5 mg·L−1), and despite the high‑nitrogen ratios of CODt:TN:TP (100:15:1.7).

Aerobic granular sludge development using diatomite for low-strength wastewater treatment

This paper presents an assessment of the start-up performance of aerobic granular sludge (AGS) for the treatment of low-strength (chemical oxygen demand, COD < 200mg/L) domestic wastewater by the application of a diatomite carrier. The feasibility was evaluated in terms of the start-up period and stability of the aerobic granules as well as COD and phosphate removal efficiencies. A single pilot-scale sequencing batch reactor (SBR) was used and operated separately for the control granulation and granulation with diatomite. Complete granulation (granulation rate ≥ 90%) was achieved within 20days for the case of diatomite with an average influent COD concentration of 184mg/L. In comparison, control granulation required 85days to accomplish the same feat with a higher average influent COD concentration (253mg/L). The presence of diatomite solidifies the core of the granules and enhances physical stability. AGS with diatomite recorded the strength and sludge volume index of 18 IC and 53mL/g suspended solids (SS) which is superior to control AGS without diatomite (19.3 IC, 81mL/g SS). Quick start-up and achievement of stable granules lead to an efficient COD (89%) and phosphate removal (74%) in 50days of bioreactor operation. Interestingly, this study revealed that diatomite has some special mechanism in enhancing the removal of both COD and phosphate. Also, diatomite has a significant influence on microbial diversity. The result of this research implies that the advanced development of granular sludge by using diatomite can provide promising low-strength wastewater treatment.

A desiccation compound as a biofilm- and necrosis-removing agent: a case series.

A new compound, Debrichem (DEBx Medical BV, the Netherlands), a topical desiccation agent (TDA), is an active gel that contains an acidic species with a potent hygroscopic action. When in contact with microorganisms and necrosis, rapid desiccation and carbonisation of the proteins in these microorganisms, as well as of the extracellular matrix of biofilms and necrosis, occurs. The resulting 'precipitate' rapidly dislodges from the wound bed, resulting in a clean wound which granulates, which is a prerequisite for healing by secondary intention. In a retrospective study, a series of mostly large and hard-to-heal lesions of different aetiologies were treated with a one-time application of the TDA, followed by weekly dressing changes. Of the total of 54 lesions included in this case series, 22 were diagnosed as venous leg ulcers (VLUs), 20 as diabetic foot ulcers (DFUs), nine as post-traumatic, hard-to-heal lesions, two as vascular ulcers and one as an ischaemic ulcer. All of the VLUs, 75% of the DFUs and all of the other lesions reached complete granulation. The use of a TDA may contribute to the consistent, fast and easy removal of both biofilms and necrosis, and hence to wound healing.

Effect of Seed Sludge Type on Aerobic Granulation, Pollutant Removal and Microbial Community in a Sequencing Batch Reactor Treating Real Textile Wastewater.

The aerobic granulation, pollutant removal, and microbial community in real textile wastewater (TWW) treatment were compared using conventional activated sludge (CAS) and preformed aerobic granular sludge (AGS) in synthetic wastewater as seed in two reactors, reactor-1 (R1) and reactor-2 (R2), respectively. The results showed that complete granulation was achieved in R1 (sludge volume index at 5 min (SVI5) and 30 min (SVI30): 19.4 mL/g; granule size: 210 μm) within 65 days, while it only required 28 days in R2 (SVI5 and SVI30: 27.3 mL/g; granule size: 496 μm). The removal of COD, NH4+-N and TN in R1 (49.8%, 98.8%, and 41.6%) and R2 (53.6%, 96.9%, and 40.8%) were comparable in 100% real TWW treatment, but stable performance was achieved much faster in R2. The real TWW had an inhibitory effect on heterotrophic bacteria activity, but it had no inhibition on ammonia-oxidizing bacteria activity. AGS with a larger particle size had a higher microbial tolerance to real TWW. Furthermore, filamentous Thiothrix in the AGS in R2 disappeared when treating real TWW, leading to the improvement of sludge settleability. Thus, seeding preformed AGS is suggested as a rapid start-up method for a robust AGS system in treating real TWW.

How weak static magnetic field contributes to rapid granulation and better performance of microalgal-bacterial granular sludge?

Microalgal-bacterial granular sludge (MBGS) has received considerable attention as an emerging sustainable process for wastewater treatment, whereas achieving rapid granulation is still challenging. Herein, we applied a static magnetic field (5 mT) to accelerate MBGS granulation in photo-sequencing batch reactors (PSBRs). Results showed that complete granulation of MBGS in the reactor with magnetic field (RM) was achieved 20 days before that in the control reactor (RC). The magnetic field significantly promoted microbial growth, sludge settleability and granule density. The treatment performance for COD (84.1 %–96.7 %), ammonium (91.7 %–100 %) and phosphorus (71.5 %–83.3 %) was efficient and similar in both reactors. However, the volumetric removal rate for total nitrogen (TN) was greatly improved by magnetic field due to increased nitrogen assimilation and denitrification. Moreover, mature MBGS in RM showed higher specific oxygen production rate (SOPR) and specific oxygen uptake rate (SOUR), approximately 90 % and 16 % greater than those in RC. The accumulation of metal ions (iron and calcium), the enhanced production of extracellular polymeric substances (EPS, especially proteins (PN)), and the enrichment of functional bacteria (EPS producers and potential denitrifiers) and phototrophs (Tetradesmus, Monoraphidium and Desmodesmus) contributed to rapid granulation and better performance of MBGS. This study provides an economic, effective and environmental-friendly method for rapid cultivation of MBGS, which would be helpful for large scale applications of MBGS.

Formation and stability of aerobic granular sludge in a sequential batch reactor for the simultaneous removal of organic matter and nutrients from low-strength domestic wastewater

Simultaneous removal of organic matter, nitrogen, and phosphorus, via simultaneous nitrification and denitrification (SND) and enhanced biological phosphorus removal processes, was evaluated in a pilot-scale sequential batch reactor. The focus was on granule's morphology, stability, microbiological composition, and reactor performance while treating diluted domestic wastewater with total chemical oxygen demand (CODt) of ≈ 200 mg.L-1. The applied organic loading rate was 0.9 ± 0.3 kg CODt.m−3.d−1 in the experiment. Aerobic granular sludge developed gradually. After 87-day operation, granules (diameter ≥ 0.2 mm) were ≥ 50 % of the biomass, and after 168 days, complete granulation was obtained (≥ 80 % of biomass). In the third period (days 168–247, complete granulation), mixed liquor biomass reached a volatile suspended solids (VSS) concentration of 1.2 ± 0.3 g VSS.L−1, with the granules remaining stable until the experimental end. In this period, low effluent concentrations of COD, nitrogen (NH4+-N, NO2−-N and NO3−-N) and phosphate (PO43—P) were obtained (mg.L−1): 36 ± 11; 4 ± 5; 3 ± 3, 4 ± 5; and 0.9 ± 0.4, respectively. COD, NH4+-N, and PO43−-P removal efficiencies (%) were 80 ± 11; 83 ± 20; and 55 ± 24, respectively. Heterotrophic nitrification and SND were observed, resulting in a process efficiency of 31 % even with dissolved oxygen applied to saturation. The phosphate removal was mainly attributed to denitrifying phosphorus accumulating organisms. Pseudomonas, the dominant genus found, acted in nitrogen and phosphorus removal. Pseudoxanthomonas also assisted in phosphorus removal. Bacterial communities in the flocs (≈ 20 % of biomass) during the last period were similar to those in the granules; therefore, they constituted the basis for granule formation, directly contributed to the simultaneous good removal of organic matter and nutrients.

Characterization of Immunogenicity Associated with the Biocompatibility of Type I Collagen from Tilapia Fish Skin.

Collagen from fish has been proven to have a low antigenicity that has no difference in the genetic codes compared with mammalian-based collagen. This study was designed to investigate the impact of tilapia skin collagen on immunogenicity and biocompatibility in vivo and in vitro. The structural characteristics of both acid-soluble and pepsin-soluble collagen (ASC and PSC), determined using SDS-PAGE and atomic force microscopy imaging experiments, revealed that the collagen had the basic characteristics of type I collagen (COL-I). The in vitro biocompatibility of the collagens showed good cell proliferation against human foreskin fibroblast (HFF-1) cells. PSC and ASC were considered to be almost non-hemolytic biomaterials with favorable blood compatibility in hemolysis tests. The in vivo antigenicity of the collagen in an ICR mouse model evoked an acceptable specific inflammatory response compared to bovine collagen. The implant’s position had developed a complete granulation tissue and the sponge disappeared after 8 weeks. The level of cytokines produced by the COL-I immune response was much lower than bovine collagen, which indicated the appropriate implantable property and biodegradability of the collagens. In conclusion, the tilapia COL-I has a lower immunogenicity with better compatibility than bovine COL-I and is a potential alternative to conventional mammalian collagens in biomedical uses.

The effect of human recombinant epidermal growth factor in the treatment of diabetic foot ulcers

Objectives. Diabetic foot ulcer (DFU) is one of the most important and common complication of type 2 diabetes mellitus (T2DM). A new therapy, consisting of intralesional administration of human recombinant epidermal growth factor (hrEGF), has been suggested to accelerate wound healing and prevent amputations. The effect of hrEGF on DFU treatment was investigated in this study. Materials and Methods. 20 patients with DFU were included in this study, all of whom were receiving insulin treatment for T2DM. In addition, they received intralesional therapy with a dose of 75 μgr of hrEGF, three times a week. Results. In 18 patients, complete granulation response was achieved in approximately 3,3 weeks. There were 2 cases of recurrence at 6 months after EGF treatment. Between 6 and 12 doses of epidermal growth factor were used for this study. The most common side effects were tremor, chills, pain and burning at the site of administration. Conclusions. Our study shows that intralesional administration of hrEGF in T2DM can prevent amputations in DFU and also accelerate wound healing. Thus, intralesional application of hrEGF should be an option for standard care, as a second line of treatment (given its cost-effectiveness) when appropriate.

Ultrafiltration of aerobic granular sludge bioreactor effluent: Fouling potentials and properties

The integration of low-pressure membrane filtration and aerobic granular sludge (AGS) reactor leads to a novel environmental biotechnological process with great potential to control membrane fouling and demonstrate good wastewater treatment performance. However, membrane fouling mechanisms in the AGS-based membrane bioreactor (MBR) lack systematic elaboration. In the present work, a bench-scale AGS reactor was operated for 8 months to investigate the effects of granule evolution, initial water flux, and membrane material on membrane fouling behavior and reversibility. After 143 days of operation, complete granulation was successfully achieved in the AGS reactor, which showed 97.6 ± 1.7% organic degradation, 94.3 ± 2.0% NH3-N removal, 90.6 ± 0.8% total nitrogen removal, and 98.9 ± 1.0% PO4-P removal. The remarkable AGS effluent quality reduced the fouling layer formation compared to the filtration occurred before complete granulation. The combined cake-complete model demonstrated that the dominant fouling mechanism is cake layer formation. The polyethersulfone (PES) membrane exhibited a better antifouling performance than the polyvinylidene fluoride membrane, regardless of the AGS effluent composition. The experimental data suggest the existence of a threshold flux for fouling reversibility when PES membrane is applied to treat the AGS effluent. Combining physical cleaning and operating under the threshold flux can effectively control the fouling degree in treating the AGS effluent by UF membrane. This, in turn, can reduce the operating cost caused by chemical cleaning and membrane replacement. Overall, the results provide comprehensive insights into the membrane fouling mechanisms and control strategy in a side-stream AGS-MBR and will contribute to the large-scale application of AGS-MBR technology in wastewater treatment.

Unveiling significance of Ca2+ ion for start-up of aerobic granular sludge reactor by distinguishing its effects on physicochemical property and bioactivity of sludge

Almost all of the aerobic granular sludge (AGS) reactors were fed on certain amounts of Ca2+ ion, but whether and why it was necessary for reactor start-up remain unknown. Herein, this study conducted a set of comparative experiments in three AGS reactors, which were operated in parallel with Ca2+ addition in R3, hydroxyapatite (HAP) addition in R1, and without any forms of Ca addition in R2. Results showed that R3 not only achieved the complete granulation of sludge, but exhibited superior performance of COD and nutrient removal. In contrast, R1 had a slightly quicker granulation rate than R3 (R1: 0.07 day−1; R3: 0.06 day−1), but the formed granules could not efficiently degrade pollutants. In R2, both sludge granulation and pollutants removal did not proceed normally. Further investigations found that the Ca2+ ion acted in three ways: (1) it increased inorganic composition of sludge to promote granulation; (2) the transformed HAP strengthened stability of granular structure; (3) it ensured bioactivity of granules by driving enrichment of functional microbes and synthesis of metabolism enzymes. Overall, this study systemically proved significance of Ca2+ ion for the start-up of AGS reactors and its influencing mechanisms on different properties of granules.

802 A retrospective study: rapid removal of biofilm and necrosis with a hygroscopic chemical debriding compound

IntroductionRemoving necrosis and biofilm is an essential step in the treatment of all lesions. A new debriding compound (TDA) uses a hygroscopic mechanism to reach this goal: when in contact with biofilm and necrosis this causes desiccation, with subsequent dissolution of these compounds.MethodsIn a retrospective proof-of-principle study the results of a one-time application of TDA in 54 serious foot and leg lesions, mainly diabetic and venous ulcers, were analyzed.ResultsOutcomes were positive: at study end: 50 out of 54 lesions (92.5%) showed complete granulation and in 40 out of 54 lesions (74.0%) complete reepithelialization was reached.TDA efficacy is represented by three cases. In the first one, an 83-year-old diabetic female with sever peripheral arterial disease and status post-toes-amputation suffered from a gangrenous lesion of the left foot. A second case involved a 77-year-old female who had a non-healing, post-trauma lesion over the Achilles tendon, and the last case entails an 81-year-old male with a non-healing lesion on the left lower leg. All patients showed very rapid debridement and subsequent healing and reepithelializationConclusionsTypically, diabetic, and venous ulcers require repeated debridement and treatment of the biofilm is notoriously difficult. It also takes a long time before the woundbed is healthy enough to start to granulate and, subsequently, epithelialize. The results, obtained in this study, indicate that a one-time application of TDA is highly effective for “jumpstarting” wound healing.

Effect of magnetic field intensity on aerobic granulation and partial nitrification-denitrification performance

Magnetic field, acknowledged as a sustainable approach, is a promising method to improve the formation, stability and treatment performance of aerobic granular sludge (AGS). In this study, partial nitrification-denitrification was achieved in three AGS sequencing batch reactors (SBRs), and the effect of magnetic field intensity on AGS formation and partial nitrification-denitrification performance were investigated. 50 mT magnetic field could accelerate complete granulation time from 45 d (0 mT) to 30 d (50 mT) by promoting the settling ability of AGS and stimulating the secretion of extracellular polymeric substances (EPS). With 50 mT magnetic field, partial nitrification-denitrification in AGS was enhanced, and the removal efficiency of chemical oxygen demand (COD), NH4+-N and TN increased by 7.6%, 26.2% and 41.5% comparing with the control (0 mT). Magnetic field balanced the dominant genera Thauera, Flavobacterium, Chryseobacterium and Meganema, which further enhanced the aerobic granulation and partial nitrification-denitrification in AGS. Thus, the application of magnetic field is reliable for accelerating aerobic granulation and enhancing partial nitrification-denitrification process.

A novel strategy for rapid development of a self-sustaining symbiotic algal-bacterial granular sludge: Applying algal-mycelial pellets as nuclei

Algal-bacterial granular sludge (ABGS) is a promising technology for wastewater treatment, benefiting from the synergetic interactions between algae and bacteria. However, the rapid start-up of the ABGS system is not trivial. Herein, a novel strategy was proposed by applying the algal-mycelial pellets (AMPs) as the primary nuclei for accelerating the development of a self-sustaining symbiotic ABGS system. The results indicated that by using this strategy complete granulation was shortened to 12 days, much shorter than the control system without AMPs dosage (28 days). The ABGS had a large particle diameter (3.3 mm), compact granular structure (1.0253 g/mL), and excellent settleability (SVI30 of 53.2 mL/g). Moreover, 98.6% of COD, 80.8% of TN and 80.0% of PO43−-P were removed by the ABGS. The nuclei of targeted algae (Chlorella) and filamentous fungi (Aspergillus niger), the enhanced production of extracellular polymeric substances (especially proteins) and the enrichment of functional bacteria (such as Neomegalonema and Flavobacterium) facilitated the granules development. The low surface free energy (-69.56 mJ/m2) and energy barrier (89.93 KT) were the inherent mechanisms for the strong surface hydrophobicity, the easy bacterial adhesion, and the short granulation period. This study provides an economically feasible approach to accelerate ABGS granulation and sustain system stability.

Secondary Intention Healing Over Exposed Bone on the Scalp, Forehead, and Temple Following Mohs Micrographic Surgery.

Removal of skin cancers on the scalp, forehead, and temple can result in surgical defects with exposed bone. In such cases, reconstruction becomes challenging due to limited vascularity for flap or graft repair. Demonstrate the usefulness of secondary intention healing of scalp, forehead, and temple defects over exposed bone. A retrospective case series of 41 patients who had Mohs Micrographic Surgery with post-surgical scalp, forehead, or temple defects involving exposed bone. These patients then underwent secondary intention healing. 90% of patients successfully healed. Average time to complete granulation was 92 days, and average time to full re-epithelialization was 186 days. Visual analog scale assessment of final scar quality resulted in 57% being good, 35% being fair, and 8% being poor. No patient had infection or other serious complication. Mean follow-up duration was 272 days. This case series shows the viability of secondary intention healing of scalp wounds over exposed bone. Study power was not adequate to predict time to complete healing based on defect size, or allow association of patient factors with the risk of nonhealing. Managing patient expectations, and emphasizing the importance of early occlusive wound care is paramount for healing success.

Biological Therapy on Infected Traumatic Wounds: A Case-Control Study.

Background:Traumatic wound is a great challenging issue to surgeons, because of large in size, heavily contaminated, infected and unscenic. Infection proceeded to progressive tissue necrosis, septicemia, organ failure or even death. Majority has polymicrobial infections. Bacteriohage therapy will have revolutionized in the treatment of wound. The present study was planned to evaluate the efficacy of topical bacteriophage therapy on large traumatic wounds in comparison with conventional therapy. Methods:The Study conducted from Sept. 2018 to July 2020. Samples between 12- 60 years was taken into study. Customized bacteriophage applied over the wound after serial debridement in case and conventional dressing in control. Fifty four wounded person met the clinical inclusion criteria; 27 in each group. Wound swab and tissue biopsy was taken for bacterial isolation. Isolated specific phage was applied over the wound on alternate day till the wound become sterile and fit for further definitive management. Results: A significant and rapid improvement was observed in wound healing in cases then control group. Average number of day required for complete granulation of wound and attaining sterility was half in cases then control. The hospital stay of the patients on BT was half (20days) than those on CT (40 days). The financial analysis also favours the BT over CT as only 1/third expenditure incurred in BT group as compared to CT Conclusion:Topical Bacteriophage therapy is efficient, effective to clearing the infection in shorter length of time and cost effective for infected traumatic wounds as compared to conventional dressing.

Bio-carrier–enhanced aerobic granulation: Effects on the extracellular polymeric substances production and microorganism community

In this study, the strengthening effect of bio-carrier inoculation in the process of aerobic granulation and its influence on the microbial secretion of extracellular polymeric substances (EPS) has been systematically explored, to further understand and perfect the rapid granulation mechanism. Complete granulation was achieved within 15 days, and the granule morphology realized in a reactor inoculated with the bio-carrier (R1) was better than that in the control group (R2), in which complete granulation was not achieved during the entire operation period. However, AGS gradually disintegrated after the 20th day because of the strong shearing force, the crushed AGS enhanced granulation, however did not ensure stability. The average EPS content in R1 20 mg﹒gVSS−1 higher than that in R2, and the protein (PN) content changes around 41.23–82.56 mg﹒gVSS−1 during the granulation process. This indicates that the bio-carrier stimulates microorganisms to secrete more EPS, and PN may have a greater effect on the aggregation of microorganisms. The results showed that the addition of the bio-carrier shortened the AGS granulation time, and increased the EPS content, and the broken AGS played an auxiliary role as the nucleus for floc attachment.