Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 17 de 17
Filter
1.
J Head Trauma Rehabil ; 38(6): E414-E423, 2023.
Article in English | MEDLINE | ID: mdl-37115938

ABSTRACT

OBJECTIVE: To assess the performance on the Buffalo Concussion Treadmill and Bike Tests in nonathletic people following a mild-to-moderate traumatic brain injury. SETTING: An outpatient rehabilitation clinic. PARTICIPANTS: Forty-nine patients with mild-to-moderate traumatic brain injury who underwent the Buffalo Concussion Treadmill or Bike Test as usual clinical care. DESIGN: A retrospective clinical audit. MAIN MEASURES: Demographics and brain injury-specific clinical data, Depression Anxiety Stress Scale; Rivermead Post-Concussion Symptom Questionnaire, and performance outcomes on the Buffalo Concussion Treadmill or Bike Test. RESULTS: Forty-nine patients (mean age: 33.7 ± 13.0 years), on average 56.2 ± 36.4 days post-injury, completed the Buffalo Concussion Treadmill or Bike Test. Fourteen patients stopped the test due to symptom exacerbation with a mean test duration of 8.1 ± 4.5 minutes, reaching an age-predicted maximum heart rate of 72.9% ± 12.4% and reporting a rating of perceived exertion of 13.4 ± 2.2. Those who terminated the test for other reasons had a significantly longer test duration (14.0 ± 4.7 minutes, P = .01), with a higher age-predicted maximum heart rate (83.3% ± 12.8%, P = .01) and rating of perceived exertion (17.0 ± 2.5, P = .01). Within the group who stopped for other reasons, 10 were due to symptoms deemed unrelated to the injury at the time of the test and 2 were stopped by the therapist for safety reasons. A significant but weak correlation between heart rate and rating of perceived exertion existed only for those who terminated the test for other reasons ( r = 0.38, P = .02). Overall, a shorter test duration was associated with higher scores of both self-reported depression ( r = -0.41, P < .01) and late postconcussion symptoms ( r = -0.40, P < .01). CONCLUSION: The Buffalo Concussion Treadmill or Bike Test can be used in the nonathletic mild-to-moderate traumatic brain injury population to differentiate between those who experience symptom exacerbation during exercise and those who do not based on symptom exacerbation, test duration, and poor perception of exertion. Further research is required to determine whether other reasons for test termination are related to the injury.


Subject(s)
Brain Concussion , Brain Injuries, Traumatic , Post-Concussion Syndrome , Humans , Young Adult , Adult , Middle Aged , Retrospective Studies , Bicycling , Symptom Flare Up , Brain Concussion/diagnosis , Brain Concussion/rehabilitation , Brain Injuries, Traumatic/diagnosis
2.
NeuroRehabilitation ; 51(2): 185-200, 2022.
Article in English | MEDLINE | ID: mdl-35527580

ABSTRACT

BACKGROUND: Recent research recommends physical exercise rather than rest following a mild traumatic brain injury (mTBI). OBJECTIVE: To determine the effect of physical exercise on persistent symptoms in people with mTBI. METHODS: A search of randomized controlled trials was conducted in CINAHL, Cochrane Library, EMBASE, MEDLINE, SportDiscus and Web of Science, from 2010 to January 2021. Studies were included if they described the effects of a physical exercise intervention in people with mTBI on persistent symptoms. Study quality, intervention reporting, and confidence in review findings were assessed with the CASP, TIDieR and GRADE respectively. RESULTS: 11 eligible studies were identified for inclusion. Study interventions broadly comprised of two categories of physical exercise, i.e., aerobic (n = 8) and vestibular (n = 3). A meta-analysis (n = 3) revealed the aerobic exercise group improvement was significantly larger compared to the usual care group -0.39 (95% CI: -0.73 to -0.05, p = 0.03). Only three studies using vestibular exercise reported on persistent symptoms and yielded mixed results. CONCLUSIONS: This study demonstrated that the use of aerobic exercise is supported by mixed quality evidence and moderate certainty of evidence, yet there is limited evidence for the use of vestibular exercise for improving persistent symptoms in people with mTBI.


Subject(s)
Brain Concussion , Brain Concussion/diagnosis , Exercise , Humans , Physical Therapy Modalities , Quality of Life , Randomized Controlled Trials as Topic
3.
Clin Rehabil ; 36(1): 125-132, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34313149

ABSTRACT

OBJECTIVE: To assess (1) step count accuracy of the Fitbit Zip, compared to manual step count, in people receiving outpatient rehabilitation, in indoor and outdoor conditions, and (2) impact of slow walking speed on Fitbit accuracy. DESIGN: Observational study. SETTING: A metropolitan rehabilitation hospital. SUBJECTS: Adults (n = 88) attending a subacute rehabilitation outpatient clinic with walking speeds of between 0.4 and 1.0 m/s. INTERVENTIONS: Two 2-minute walk tests, one indoors and one outdoors, completed in random order. MAIN MEASURES: Step count recorded manually by observation and by a Fitbit Zip, attached to the shoe on the dominant or non-affected side. Subgroup analysis included assessment accuracy for those considered limited community walkers (slower than 0.8 m/s) and those considered community walkers (faster than 0.8 m/s). RESULTS: The Fitbit significantly (P < 0.05) undercounted steps compared to manual step count, indoors and outdoors, with percentage agreement slightly higher outdoors (mean 92.4%) than indoors (90.1%). Overall, there was excellent consistent agreement between the Fitbit and manual step count for both indoor (ICC 0.83) and outdoor (ICC 0.88) walks. The accuracy of the Fitbit was significantly (P < 0.05) reduced in those who walked slower than 0.8 m/s outdoors (ICC 0.80) compared to those who walk faster than 0.8 m/s (ICC 0.90). CONCLUSIONS: The Fitbit Zip shows high step count accuracy with manual step count in a mixed subacute rehabilitation population. However, accuracy is affected by walking speed, with decreased accuracy in limited community walkers.


Subject(s)
Fitness Trackers , Monitoring, Ambulatory , Adult , Humans , Reproducibility of Results , Walking , Walking Speed
4.
Age Ageing ; 50(6): 2025-2030, 2021 11 10.
Article in English | MEDLINE | ID: mdl-34120167

ABSTRACT

BACKGROUND: The frequency and impact of undiagnosed benign paroxysmal positional vertigo (BPPV) in people identified with high falls risk has not been investigated. OBJECTIVE: To determine the frequency and impact on key psychosocial measures of undiagnosed BPPV in adult community rehabilitation outpatients identified with a high falls risk. DESIGN: A frequency study with cross-sectional design. SETTING: A Community Rehabilitation Program in Melbourne, Australia. SUBJECTS: Adult community rehabilitation outpatients with a Falls Risk for Older People in the Community Screen score of four or higher. METHODS: BPPV was assessed in 34 consecutive high falls risk rehabilitation outpatients using the Dix-Hallpike test and supine roll test. Participants were assessed for anxiety, depression, fear of falls, social isolation and loneliness using the Hospital Anxiety and Depression Scale, Falls Efficacy Scale-International and De Jong Gierveld 6-Item Loneliness Scale. RESULTS: A total of 18 (53%; 95% confidence interval: 36, 70) participants tested positive for BPPV. There was no significant difference between those who tested positive for BPPV and those who did not for Falls Risk for Older People in the Community Screen scores (P = 0.555), Hospital Anxiety and Depression Scale (Anxiety) scores (P = 0.627), Hospital Anxiety and Depression Scale (Depression) scores (P = 0.368) or Falls Efficacy Scale-International scores (P = 0.481). Higher scores for the De Jong Gierveld 6-Item Loneliness Scale in participants with BPPV did not reach significance (P = 0.056). CONCLUSIONS: Undiagnosed BPPV is very common and associated with a trend towards increased loneliness in adult rehabilitation outpatients identified as having a high falls risk.


Subject(s)
Accidental Falls , Benign Paroxysmal Positional Vertigo , Accidental Falls/prevention & control , Aged , Anxiety Disorders , Benign Paroxysmal Positional Vertigo/diagnosis , Benign Paroxysmal Positional Vertigo/epidemiology , Cross-Sectional Studies , Humans , Outpatients
5.
Hong Kong J Occup Ther ; 34(2): 73-82, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34987345

ABSTRACT

INTRODUCTION: Health care expenditure has rapidly increased in Australia. Effective management of occupational therapy services is required to meet clinical demand. Improving our understanding of factors which influence occupational therapy service delivery is a vital step to manage workload distribution and optimise service efficiency. This study aims to examine the influence of patient sociodemographic characteristics, diagnosis and functional independence on the utilisation of occupational therapy resources in hospital inpatients over 18 years old. METHODS: Prospective, cross-sectional, observational cohort study of 4549 inpatients from three hospital sites in Melbourne, Australia. Data extracted from organisational databases and included in this study were: patient demographics, diagnosis, functional level assessed using the SMAF (Functional Autonomy Measurement System) and occupational therapy time-use. Data were analysed using univariable and multivariable modelling. RESULTS: Occupational therapy time-use was significantly associated with all variables included in analysis (p < 0.05). For each variable the amount and direction of effect differed between hospital sites. The SMAF was the only variable consistently associated with occupational therapy time-use. Higher occupational therapy time-use was associated with lower functional independence (leading to a 3.5 min increase in median occupational therapy time for every unit decrease in SMAF score). CONCLUSIONS: Management of resources within busy hospitals require knowledge of factors associated with occupational therapist time-use. This study identified that time-use could in part be predicted by functional independence, diagnosis and sociodemographic characteristics. Occupational therapy managers can use this information to support decision making while acknowledging other patient and therapist level factors also influence time-use.

6.
Brain Inj ; 31(13-14): 1840-1845, 2017.
Article in English | MEDLINE | ID: mdl-28829629

ABSTRACT

PRIMARY OBJECTIVE: To investigate if patients with traumatic brain injury, who are discharged to the community before emergence from post-traumatic amnesia (PTA), experience more adverse outcomes than those discharged after emergence from PTA. RESEARCH DESIGN: A retrospective review of previously collected data and medical records. METHODS AND PROCEDURES: Occurrences of adverse events including hospital readmissions, disengagement from follow-up services, non-compliance with discharge precautions, support system breakdown or undue carer strain at the post-discharge clinic review were recorded. The Glasgow Outcome Scale - Extended (GOS-E) and Supervision Rating Scale (SRS) were completed, retrospectively. Twenty-seven patients discharged to the community, prior to emergence from PTA, were compared to 20 patients discharged within seven days of emergence from PTA. MAIN OUTCOMES AND RESULTS: Patients discharged prior to emergence from PTA did not experience an increase in adverse outcomes and showed a higher level of engagement in follow-up services (p = 0.015). There was no difference between groups in the improvements from discharge to clinic review on the GOS-E (p = 0.113) and SRS (p = 0.165). CONCLUSIONS: Patients can be discharged prior to emergence from PTA, if all other discharge criteria have been met, without an increase in adverse outcomes.


Subject(s)
Amnesia/etiology , Brain Injuries, Traumatic/complications , Outcome Assessment, Health Care , Patient Discharge , Adult , Brain Injuries, Traumatic/rehabilitation , Female , Glasgow Coma Scale , Humans , Male , Middle Aged , Residence Characteristics , Retrospective Studies , Statistics, Nonparametric , Young Adult
7.
Mult Scler Relat Disord ; 16: 15-21, 2017 Aug.
Article in English | MEDLINE | ID: mdl-28755679

ABSTRACT

BACKGROUND: Walking in the real-world involves negotiating challenging or uneven surfaces, including sand. This can be challenging for people with Multiple Sclerosis (PWMS) due to motor deficits affecting the lower extremities. The study objective was to characterise kinematic gait adaptations made by PWMS when walking on sand and describe any immediate post-adaptation effects. METHODS: 17 PWMS (mean age 51.4 ± 5.5, Disease Steps 2.4 ± 1.0), and 14 age-and gender matched healthy adults (HA) took part in a case-control study. 3D gait analysis was conducted using an eight-camera Vicon motion capture system. Each participant completed walking trials over level ground (baseline), sand (gait adaptation response), and again level ground (post-adaptation). Spatiotemporal data and kinematic data for the hip knee and ankle were recorded. RESULTS: At baseline PWMS showed significantly less total lower limb flexion (p<0.05) compared to HA. PWMS adapted to walking on sand by significantly increasing hip and knee flexion and ankle dorsiflexion (p<0.05) during swing, resulting in an overall 23° greater total lower limb flexion (p<0.05), reaching values within normal range. During the return to level ground walking values of temporal-spatial and kinematic parameters returned towards baseline values. CONCLUSIONS: PWMS adapted to walking on sand by increasing lower limb flexion during swing, and returned to their gait pattern to near baseline levels, in a manner similar to but with values not equalling HA. Further work is required to determine whether this mode of walking has potential to act as a gait retraining strategy to increase flexion of the lower limb.


Subject(s)
Gait , Multiple Sclerosis/physiopathology , Adaptation, Physiological , Biomechanical Phenomena , Case-Control Studies , Female , Gait/physiology , Humans , Imaging, Three-Dimensional , Lower Extremity/physiopathology , Male , Middle Aged , Physical Stimulation
8.
Disabil Rehabil Assist Technol ; 12(6): 560-572, 2017 08.
Article in English | MEDLINE | ID: mdl-28612678

ABSTRACT

PURPOSE: To assess the orthotic and therapeutic effects of prolonged use of functional electrical stimulation (FES) on fatigue induced gait patterns in people with Multiple Sclerosis (MS). METHOD: Thirteen people with MS completed 3D gait analysis with FES off and on, before and after a fatiguing 6-minute walk, at baseline and after 8 weeks of use of FES. RESULTS: Eleven participants completed all testing. An orthotic effect on gait was not evident on first use of FES. However, therapeutic effects on gait after 8 weeks use were generally positive, including increases in walking speed due to improved neuromuscular control and power generated at the hip and ankle of the more affected limb. The action of FES alone was not sufficient to overcome all fatigue related deficits in gait but there was evidence 8 weeks use of FES can ameliorate some fatigue effects on lower limb kinetics, including benefits to ankle mechanics involved in generating power around push-off during stance. CONCLUSIONS: Eight-weeks of FES can benefit the gait pattern of people with MS under non-fatigued and fatigued conditions. Implications for rehabilitation In some people with MS prolonged use of FES may be necessary before observing positive orthotic effects. Improvements in the neuromuscular control of the more affected lower limb may develop with prolonged use of FES in people with MS. Only some therapeutic benefits of FES are maintained during fatigued walking in people with MS. FES may be considered as a gait retraining device as well as an orthotic intervention for people with MS.


Subject(s)
Electric Stimulation Therapy , Multiple Sclerosis/physiopathology , Multiple Sclerosis/rehabilitation , Muscle Fatigue/physiology , Orthotic Devices , Adult , Ankle Joint , Biomechanical Phenomena , Electric Stimulation Therapy/methods , Female , Gait , Hospitals , Humans , Lower Extremity/physiopathology , Male , Middle Aged , South Australia , Treatment Outcome , Walking
9.
Disabil Health J ; 9(2): 320-3, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26905972

ABSTRACT

BACKGROUND: Activity monitoring is used for motivation and assessing patients in the rehabilitation setting. Monitors available on the market have not been assessed for accuracy at walking patterns seen in the clinical setting. OBJECTIVES: To assess the accuracy of the Fitbit Zip device at different anatomical locations at walking speeds, step length, and cadence similar to those seen in clinical rehabilitation populations. METHODS: Ten healthy participants completed 3 sets of 12 combinations of speed and cadence ranging from 0.2 m/s at 48 steps per minute to 1.0 m/s at 120 steps per minute along a 20 m walkway. Step length was controlled by ground markings and cadence was controlled by a metronome. Five Fitbit Zip devices were concurrently worn at the chest, hip, shin, ankle and forefoot. Percent accuracy for each location and walking condition combination were calculated. RESULTS: At the chest and hip the Fitbit has poor accuracy below 0.7 m/s, however when worn distally, can be accurate to 5.5% at speeds as slow as 0.5 m/s. CONCLUSIONS: For patient populations with slow walking speed, activity monitoring with the Fitbit can be achieved provided the device is located distally on the lower limb.


Subject(s)
Disabled Persons/rehabilitation , Monitoring, Ambulatory/instrumentation , Walking Speed , Walking , Adult , Female , Humans , Lower Extremity , Male , Monitoring, Ambulatory/methods , Monitoring, Ambulatory/standards , Reference Values , Reproducibility of Results , Young Adult
10.
Br J Oral Maxillofac Surg ; 54(6): 716-7, 2016 07.
Article in English | MEDLINE | ID: mdl-26608688
11.
Arch Phys Med Rehabil ; 96(2): 226-232.e1, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25264109

ABSTRACT

OBJECTIVE: To evaluate the effect of wearing a dorsiflexion assist orthosis (DAO) on walking distance, physiological cost, fatigue, and strength and balance measures after a modified 6-minute walk test (6MWT) in people with multiple sclerosis (MS). DESIGN: Randomized crossover trial. SETTING: Hospital Movement Laboratory. PARTICIPANTS: People with moderate MS and Expanded Disability Status Scale score of 3.7±0.7 (N=34; 26 women). INTERVENTIONS: Modified 6MWT with and without a DAO worn on the weaker leg. MAIN OUTCOME MEASURES: Distance walked, perceived fatigue, and the physiological cost of walking were compared between walking conditions. Pre- and postwalk changes in knee extensor and ankle dorsiflexor isometric strength and standing postural sway with eyes open and closed were compared between walking conditions. RESULTS: There were no differences in distance walked or perceived fatigue between the 2 walking conditions. However, there was a reduced physiological cost of walking (P<.05), a smaller reduction in knee extensor strength (P<.05), and a smaller increase in standing postural sway with eyes open (P<.01) after walking while wearing the DAO compared with walking without wearing the DAO. CONCLUSIONS: Despite not increasing walking distance or reducing perceived fatigue, the DAO reduced the physiological cost of walking and maintained knee strength and standing balance, which may have important implications for physical rehabilitation in people with MS. Further trials are required to determine whether the beneficial effects of wearing a DAO found here are maintained for longer periods.


Subject(s)
Multiple Sclerosis/physiopathology , Multiple Sclerosis/rehabilitation , Orthotic Devices , Physical Exertion/physiology , Walking/physiology , Adult , Ankle Joint/physiology , Cross-Over Studies , Exercise Test , Fatigue/physiopathology , Female , Gait/physiology , Humans , Male , Middle Aged , Multiple Sclerosis/complications , Muscle Strength/physiology , Muscle Weakness/etiology , Muscle Weakness/rehabilitation , Muscle, Skeletal/physiopathology , Postural Balance/physiology
12.
Aust Occup Ther J ; 62(2): 132-40, 2015 Apr.
Article in English | MEDLINE | ID: mdl-24762220

ABSTRACT

BACKGROUND/AIM: Home visits, used by occupational therapists to facilitate independence and enhance safety, are effective but costly and time consuming. This research aims to establish the level of agreement in equipment prescribed by occupational therapists using: digital photographs only, and using home visits and digital photographs, respectively. METHOD: Quasi-experimental methodological design conducted in private dwellings in the community in Adelaide with rehabilitation patients and their family members. The equipment recommended by occupational therapists for the toilet and bathroom using similar methods (both digital photographs from previous data; n = 5) was compared with equipment recommended using different methods (conventional home visits vs. digital photographs; n = 14). RESULTS: Percent agreement for equipment prescribed between groups, that is digital only and home visit/photography, respectively, were: 72.5/83.9% for toilet; 87.4/88.3% for bathroom and 83/87% for toilet and bathroom. Variability of agreement in the equipment prescribed showed that some items of equipment were incongruently prescribed, by both methods for toilet and bathroom areas. CONCLUSION: Using digital photographs taken by family members, patient information, and an equipment list is a reliable method of making accurate equipment prescriptions in the toilet and bathroom areas. To enhance accuracy, in-depth patient information via face-to-face interview and measurements of physical environment should be included.


Subject(s)
Disabled Persons/rehabilitation , House Calls , Occupational Therapy/methods , Photography , Prescriptions , Toilet Facilities , Adult , Aged , Aged, 80 and over , Caregivers , Decision Making , Female , Humans , Male , Middle Aged , Patient Participation
14.
Aust Health Rev ; 38(3): 265-70, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24804607

ABSTRACT

OBJECTIVE: The aim of the present study was to investigate a change in physiotherapy provision from a 5- to 7-days-a-week service on both physiotherapy and hospital length of stay (LOS) after total knee (TKR) and total hip (THR) replacement. METHODS: A retrospective analysis of a clinical database was conducted for patients who received either a TKR or THR between July 2010 and June 2012 in one regional hospital. RESULTS: There was a significant decrease in physiotherapy LOS from 5.0 days (interquartile range (IQR) 5.0-6.0 days) for a 5-day physiotherapy service, to 5.0 days (IQR 4.0-5.0 days) for 7-day physiotherapy service (U=1443.5, z=-4.62, P=0.001). However, hospital LOS was not reduced (P=0.110). For TKR, physiotherapy LOS decreased significantly by 1 day with a 7-day physiotherapy service (U=518.0, z=-4.20, P=0.001). However, hospital LOS was again no different (P=0.309). For THR there was no difference in physiotherapy LOS (P=0.060) or hospital LOS (P=0.303) between the 5- and 7-day physiotherapy services. Where physiotherapy LOS was less than hospital LOS, delayed discharge was due primarily to non-medical issues (72%) associated with hospital organisational aspects. CONCLUSIONS: Increasing the provision of physiotherapy service after TKR provides an increase in physiotherapy sessions and has the potential to reduce hospital LOS. To be effective this must align with other administrative aspects of hospital discharge.


Subject(s)
After-Hours Care , Arthroplasty, Replacement, Hip/rehabilitation , Arthroplasty, Replacement, Knee/rehabilitation , Hospitalization , Length of Stay , Physical Therapy Modalities/organization & administration , Aged , Female , Humans , Male , Queensland , Retrospective Studies
15.
J Arthroplasty ; 28(8 Suppl): 41-4, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23910510

ABSTRACT

Acetabular cup positioning is a critical factor in determining adverse clinical outcomes in THA. This evaluation was performed to determine if morbid obesity (BMI ≥35kg/m(2)) is a contributing risk factor to cup malpositioning. Two groups of patients were obtained from a local arthroplasty registry and match-controlled for gender, age, and diagnosis (n=211 morbidly obese; n=211 normal). Intraoperative data and postoperative AP pelvis and cross-table lateral radiographs were obtained for each patient. The Martell Hip Analysis Suite was used to calculate cup positioning (successful positioning defined as 30°-45° of abduction, and 5°-25° of anteversion), as well as varus-valgus alignment of the femoral stem. There was a significant correlation between morbid obesity with respect to underanteversion; using multivariate analysis, there was a trend toward a combined underanteversion/overabduction of the acetabular cup. Of all variables considered, high BMI was the most significant risk factor leading to malpositioning.


Subject(s)
Arthroplasty, Replacement, Hip , Bone Malalignment/epidemiology , Hip Prosthesis , Obesity, Morbid/complications , Osteoarthritis, Hip/surgery , Adult , Aged , Aged, 80 and over , Body Mass Index , Bone Malalignment/diagnostic imaging , Case-Control Studies , Female , Femur Neck/diagnostic imaging , Femur Neck/surgery , Hip Joint/diagnostic imaging , Hip Joint/surgery , Humans , Logistic Models , Male , Middle Aged , Radiography , Risk Factors , Treatment Outcome
16.
J Arthroplasty ; 27(10): 1766-71, 2012 Dec.
Article in English | MEDLINE | ID: mdl-22743121

ABSTRACT

Data quality standards for multicenter arthroplasty registries have been previously established. However, no studies have assessed a hospital-based arthroplasty registry. A total of 6912 hip and knee procedures were queried in a hospital-based arthroplasty registry (HJR) and an administrative research database (Research Patient Data Registry). The HJR demonstrated a 93.8% capture rate. Four hundred seventy-seven cases contained data errors, with 65.7% occurring in the HJR. Most of these conflicts were attributable to random error. Systematic miscoding of procedures was observed in both databases and was most likely due to unclear definitions of procedural classifications. Our results confirm the validity of data in the HJR and suggest that using automated data capture systems and establishing a clear consensus on procedural terminology can improve the quality of data registries.


Subject(s)
Arthroplasty , Registries/standards , Arthroplasty, Replacement, Hip , Arthroplasty, Replacement, Knee , Hospitals , Humans
17.
Bioresour Technol ; 104: 480-5, 2012 Jan.
Article in English | MEDLINE | ID: mdl-22154300

ABSTRACT

Critical cellulase and hemicellulase activities are identified for hydrolysis of ionic liquid (IL) pretreated poplar and switchgrass; hemicellulase rich substrates with largely amorphous cellulose. Enzymes from Aspergillus nidulans were expressed and purified: an endoglucanase (EG) a cellobiohydrolase (CBH), an endoxylanase (EX) and an acetylxylan esterase (AXE). ß-Xylosidase (ßX) from Selenomonas ruminantium and a commercial ß-glucosidase (ßG) from Novozyme 188 were admixed with the A. nidulans enzymes. Statistical analysis indicates that ßG and ßX activities are significant for both glucose and xylose yields for the two substrates. EG is a significant factor for glucan hydrolysis while EX is significant for xylan hydrolysis of the substrates. The CBH, which has activity on crystalline cellulose and negligible activity on amorphous cellulose, was not a significant factor in glucan hydrolysis. EX is significant in glucan hydrolysis for poplar. The addition of AXE significantly improves xylan hydrolysis for poplar but not switchgrass.


Subject(s)
Bacterial Proteins/chemistry , Cellulase/chemistry , Glycoside Hydrolases/chemistry , Ionic Liquids/chemistry , Panicum/chemistry , Populus/chemistry , Enzyme Activation , Glucans/chemistry , Hydrolysis , Substrate Specificity , Xylans/chemistry
SELECTION OF CITATIONS
SEARCH DETAIL
...